Agree on the depreciation cycle. The best time to buy these was from the late 2000s (cash for clunkers unfortunately) and up to the mid 2010s when these vehicles were seen as yesterday's news.
That being said, these trucks haven't seen MSRP value in my area. My truck's MSRP was $20,826.05 and was invoiced for $18,223.30. Adjusted for inflation from 1997 to 2023, that's $39,540.13 and $34.642.30 respectively. I've seen mint condition trucks in my area sell for 10k. A few I've seen a few 3/4 and 1 tons sell for 20k, but these trucks never move. What I really hate, and I mentioned this in my Introduction post to
@HotWheelsBurban is that I'd gladly pay $7-10k for a nice clean like new GMT400 truck/suv, I HATE that people are trying to sell their JUNK for WAAYY more than it would ever be worth. You see it all the time on FB marketplace, craigslist, offerup, gunbroker (for gun stuff) etc...
No, I'm not paying you $5K for a GMT400 pickup like mine with 200K miles, rust on all the body panels of the truck, a 6 inch Rough country lift, "33" inch tires (just say the tire size, I'm so sick of that slang term), aftermarket tow mirrors, K&N filter that's never serviced, those god awful aftermarket headlights and taillights that all yee yee boys have, aftermarket radio, and torn seat cushions that are covered by camo seat covers. A lot of times the owners don't even bother to clean the truck before selling it. Dude, at least TRY to make your truck sellable, just because there's a SMALL COLLECTORS market, doesn't mean YOURS is valuable. Honestly, I don't even think mine's that valuable either (rust, no interior lights, cracked dash, floppy headliner held in by thumb tacks etc...)
In terms of parts, there's plenty of them online, the problem is, it's a real mixed bag of quality. Dorman is trash as far as I'm concerned, TRQ (1A Auto) is the minimum I'll go for, MasterPro (O'Reillys) and Duralast (Autozone) are good and am currently using Masterpro steering everything on my truck rn with no problems. AC Delco/GM Genuine parts are getting more and more scarce. I read an article about this and it's simply bc car companies are only legally obligated to make parts for vehicles up until their factory warranties expire. So in theory, if 1999 was the last year to get a 1/2 ton, and the factory warranty was 3 years, GM could've discontinued all parts in 2002. They could've discontinued parts in 2005 for 3/4 and 1 tons bc 2002 was the last year for the C3500. The only reason they were made that long was bc GM had contracts with companies that still wanted these trucks and needed to fulfill those contracts before seizing production.
As far as 3rd gen Camaros/Firebirds, maybe I'm too young to make a comment on this (I'm 22), but I NEVER see sports cars of ANY make or model in my local yard. You'll find plenty of GMT400s or GMT800s, Ford F150s of all generations (87-14 in my experience) and Dodge Rams (94-08 in my experience) and other Full size SUVs from those platforms. S10s, Dakotas, and Rangers are also common, but less so. Sedans are usually mid size 4 door sedans and they've typically seen a terrible wreck before coming to the yard.