Depending on how many miles are on the truck I’d ask what has been done for maintenance. Transmission fluid and filter, brakes, transfer case case fluid, brakes, shocks etc.. I have a 03 and when I bought it the transmission mount was broken. I’d get it in the highway and get it up to 75 mph plus to see how it handles and it any check engine lights pop.
You might also ask if they put a transfer case shield in to protect it from a pin hole getting punched in it. If not and you buy it I would do that sometime. Those early 2000 4x4s are notorious for the transfer case having a hole punched in the top due to poor engineering by GM. There is a fix out there that prevents this from happening sonyou don’t end up driving one day and find your transfer case fluid is spilling everywhere.