The major stuff I will define as over $1000. (25% of the price you want to pay to buy)
Generally that scenario is going to be drivetrain, some suspension pieces and electronics. For these you get an inspection by some one that would do those repairs. My wife (and step daughter) has an affinity for Toyotas. (Don't go there I have many times) The 2.2l 4 cyl engine will get a significant engine oil leak that sets us back $1000 to $1500. However I have discovered if the oil is changed frequently the oil leak shows up later. I am assuming this is because the rubber in the seal hardens the rubber and with fresher oil this happens later.
Same for your scenario. Most vehicles I have ever had that may be involved in common issues ALWAYS occurred later and at higher mileage for me than the issue I found on the internet. I don't have documented proof of why and yet I am going to venture into my care of the vehicles. So a V6 with a known timing chain issue is likely discovered by the general vehicle owner that doesn't maintain the vehicle at least to manufacturer's intervals.
I hate to hammer maintenance so hard and it is a frequent thing I see on this (and any) forum regarding major systems. OP states "I have a transmission issue on a ??? model". Question how many miles on it? Answer 100,000! Q, when was it last serviced? A, never. My step daughter is right there. She only puts in gas when she has to and everything else about her car is an after thought if ever thought about!
My opinion, skip looking for a common major problem. Find a $4K vehicle that fits the bill. Change every fluid, filter, belt and hose that came on it to get a base line. Then drive and maintain to better standards than is published in the owner's manual. BTW reading & following the owner's manual goes a long way.
Sorry for the rant.
>>>>>>>>>>>>Action