Theres a sticky with this exact title. HiHoeSilver posted it for you, right in the thread.
$3K is going to be too light for something with low 100K mileage. However, Something with 200K (that's in your price range), will still go another 100K if taken cared of, and you continue to do so.
05-06 has efans, but with your budget I would keep it open to 2000-2006.
You can get cloth also (which some from hotter climates prefer), or you can always buy replacement covers, replacement seats,
From my searching here's some stuff I noticed:
Learn what the VIN digits mean (and you can some times tell more than the others just from that).
https://www.tahoeyukonforum.com/thr...tailed-vin-info-for-free.109476/#post-1306586
ENGINE: You're not getting a 6.0L for that budget, unless you can find someone looking to sell a denali quick, and you have cash to check it out right away, or maybe at an auction. You might want to look around and see if ther are any in your area that you can make it too. These vehicles can be on there quite frequently. Its a gamble, but if its low enough and you can do the work yourself to fix something nothing is too expensive that you should be down for long. See if you have any local police autions, or I like hibid.com There are some automotive only auctions too. Iaai.com is one that's easy to use. You will most likely need to be flexible with an auction on probably color, but there are can be some really good deals if you get lucky.
The 8th digit of the VIN is the engine code. The 4.8 has less power and a torque curve that doesn't kick in till way too late. At least get the 5.3, most sellers don't even know what they have. I saw more of them advertising it had a V8 (which they all do), then mention which one.
V 4.8
T 5.3
Z 5.3 FF
Not sure if you wanted 2WD, 4WD, or AWD, but being in SOCAL, probably 2WD.
Theres a lot we can go over, but we won't out of the blue. Search, and see what you come up with then ask specific questions or go into as much detail as you can, and we will try and help guide you. What will you be using it for? What mods if you any do you plan on doing to it? What is your driving history, (cars years, use, etc).
I'm going to make a guess, because it sounds like you are younger than most in here, so I'll say this: Don't take shit from anyone just because you like there vehicle. Hold firm on your ground. You don't want to blow your budget only to get caught with a major repair. If you show up with cash, like the vehicle and the smog is nearly out, tell them you'll buy it once it passes smog. It doesn't take long, and you can go and get it done right then. If its got time, and even if it doesn't, you should be able to look up the history of the vehicle. If it wasn't meant to be, don't worry, there are plenty of them out there.
Keep in mind also, that anyone who has sold a car before will tell you its a HASSLE! People call, don't know shit and want to just talk. Some people want to ask you stupid questions that don't matter, or that you have specifically written down in an ad. People say they will buy it right then, and never show up just to ghost you on the phone hours later to see if they are still coming over. There are USED car dealerships EVERYWHERE simply because people don't want to deal with selling there cars in private party and are willing to take less than what its worth not to deal with it. Then those dealerships make enough to have a profitable business by doing nothing more than washing a car, and charging for dealing with all the BS. So when you call someone and they sound short, or frustrated, its because you're probably the 10th person who called. There were probably two that didn't show up after they said they would. Six of those first nine people all asked the same thing "Is it still for sale?" After everyone of them the seller wants to say "well is the ad still up *******?" then they ask, "What's the lowest you will take?" without ever asking a single question about it or wanting to come check it out. (that is such a childish, annoying ass thing to hear). If you don't have the full amount, be honest and I'll tell you not to waste your time, or I'll think about it. Half of those who wanted to know how low you will go, are just trying to get a seller to go even lower than that and think they are negotiating from that point. If someone is asking $4K, just tell them you have $3K and if you come check it out would they even consider it? Don't waste your time or theirs if not.
So.. Start now making your list of what you want to know, (specifically what options, condition, records, problems, smog, etc... ) WRITE THIS ALL DOWN so you don't forget and its ready. Then see what they have already answered. What I personally like and like to do is call first (or text if they say they prefer it), and first thing you say, is you are interested in the vehicle, and have some questions you would like to ask, do they have a few minutes to go over it, and then hopefully arrange a time to meet and check it out if everything sounds good. I'm not telling you to do what ever they want, but if you can make it easy on them, and be straightforward, professional, and honest with them about it, (NOT dick around) you will put them in a better mood, and have your best chance at them willing to come down on the price a little.
Never check out a vehicle at night. Doesn't matter if you are in the lighting aisle at home depot, there will still be scratches and dings you won't see during the day. Personally, every vehicle I have bought we test drove it in a public area, then we met at a 24 hour licensing office if you have those near by. It costs IIRC $11 to skip the DMV line, and we had everything changed over right then and there, and that was where we exchanged cash. I made sure they knew what the plan was, (showed them a balance receipt from the ATM that day), and after the test drive got the cash, and then met them at the title place around the corner. All in, it took a couple hours, possibly over cautious, but you never know who you are dealing with if its a private party.
Carfax is only a few bucks, and some times you can find someone who can run one for you. It may not show every accident, but it will show you if its had steady mileage, if its been up north, if there are any dealer service records with a gap, if there are any liens on it (which shows someone didn't have cash for a while to keep up with maintenance).
There's a lot more, but its your turn....