The tacomas 95-04 really hold their value. I had a 98 and a 01. I wish I had never sold the 01. It was a beast and looked great.
They didn't change to much over the years on the tacos from 95 to 04. The biggest changes were grills and tail and head lights, and interiors but the most noticeable changes are in 01-04 with the newer interiors and grill and hood shapes.
The Trd package for those tacomas were shocks and a rear push button locker. Watch for ones that just have had a sticker thrown on to raise to resell value or just look cooler. Real Trds will have the rr lock button to the left of the steering wheel. And if you really want to be sure it will have the elocker next to the third member on the axle housing.
95-00 can have manual locking hubs in the front from the dealer, after 00 and it was swapped in by an owner, which isn't a bad thing.
98 was the first year for trd
4doors only came in autos
More than 3 inches of lift causes problems with from cvs, really I found about 2in was max for not tearing the boots.
Watch for bad upper or lower ball joints I had 2 friends have them fail and the front end collapsed. Very rare and and has more to do with owner not maintaining vehicle but they should probably be swapped out if boots torn or worn. Toyota parts are best for this.
Could be a way to get the price down by quoting dealer prices for swapping balljoints my guess is 1k plus and do the work yourself. Don't quote me but I don't think any special tools would be required and could be a fun father son project.
They do have frame rust problems but I think for the most part it's in areas of the country that all vehicles have frame rust problems.
Used parts for tacos can be found for a deal used at ttora.com on the forums. When I had mine I got lots of stuff from members there. It's dried up over the last ten years but still some people selling stuff.
The taco or many toyota 4x4 can get someone in over their head quick off-road as the vehicle capabilities are greater than most drivers.
Make sure your son knows safety when off-roading as he will likely go without you. Winches are dangerous make sure he knows safety, high-lifts shouldn't be used by someone not very very well informed. I saw a kid knock his teeth out with one years back.
Don't let your friends talk you into driving somewhere not safe.
O yea I forgot one more thing. Many owners wanted a j-stick transfer case instead of the push button type. I'm not sure of the exact differences but one has a 4wd button on the t-case shifter and one does not. Maybe someone else can chime in what to look for or stay away from, I'm not sure how the 4wd button works I didn't have one just the j pattern tcase shifter