Thoughts on purchasing a higher-mileage Duramax?

[CTown Duramax]

We have a diesel Guru tech at our GMC. Great guy, has said most all you mentioned. The oil consumption is a baffle in the valve cover. They replace the valve cover. Only effects 20-21's . . . . .now and charge more for it. Its not fun anymore, its offensive. I can buy anything i want, but i won't. 85K for a GM truck...its crazy. A Mercedes GLS is 97K and very luxurious and high quality. Yes they have issues as all trucks do. At 100K I'll be out of warranty and fix what breaks.

Do you know where I can find the relevant VIN ranges?