While it is customary for shops to charge retail for gaskets, that is ridiculous. If they are that dishonest, I would not trust them to check the air in my tires.
These are the current prices at Amazon.com, delivered!
View attachment 345849
If yours were mine, I would crawl under there with a ratchet and socket and gently tighten the oil pan bolts and poke around for any other loose bolts and such looking for leaks, especially around the engine oil cooler lines as they were leaking on mine at the gasket above the oil filter. We eventually replaced the lines as they were plumb wore out. If my teenage daughters can do this work, you can too. Then buy yourself a new pistol or take your wife away for the weekend with all the money you saved!