When the needed repairs are mechanical it will be quite obvious and the dealer will need to fix it or it will be hard to sell, but there are cosmetic issues and other items that falls in a gray area and it will vary from a dealer to another whether they will fix it or not.
For instance, when leather seats are slightly worn it will almost cost the same as if it was severely damages because it will be mostly repaired by sending it to an upholstery that will choose to replace the leather anyway, in this case the dealer may chose to sell the car with the seat AS-IS and the buyer may ignore the issue if the car is in a good mechanical condition.
Another example; with minor scratches that are not easy to just touch up, the dealer will have send the car to the body shop to paint at least half of the panel to be able to blend in the colors which it will cost almost the same as if it was full panel paint, so also the dealer may chose to sell the car with the heavy scratch AS-IS and the buyer may ignore the issue if the car is in a good mechanical condition.
the point is, a ripped leather seat, a large scratch on the door or a slightly sagging headliner may not be a deal breaker for some car buyer IF the car they are buying is in a good mechanical condition and the price is right.
The problem will occur when the issue is concerning the safety of the vehicle, as an example if the brakes are less than 35% and is causing noise when applying the breaks, the dealer should repair it with no questions asked, so if you go to test drive a car and the breaks doesn’t seems like in a good condition, you should be requesting the dealer to repair it or at least discount the price with a 150% of the cost of the breaks repair to compensate you for the time you will spend at the shop to repair the breaks. You will need to investigate the cost of the parts before the negotiations.
Same would apply for Tires on your car, the tires are very important to be in a good condition with good tread to be safe to drive on, if you are checking a car out to buy and you found the tires are bold and don’t have good tread, you will need to make sure it is taking care of before you start using the vehicle.
Suspensions, struts, control arms and stabilizer links are also playing a vital part for the safety of the vehicle and usually are easy to identify when test driving the car.
Here is an answer to a very important question; How can i find the best price on parts like breaks, tires and suspensions???
There is a company called , They are a leading company in selling parts also they always have offers to compete strongly in the market, if the dealer is not wiling to do the repairs himself, check out their pricing and decide how much the dealer should discount the vehicle.
Also for being a leading parts company, Prices are matched buy most retailers who give price matching guarantee, so if you are in rush to buy the parts, you can get a price from Tire Rack then get a proof of the price and take it to your local parts store and ask them to match the lowest price, trust me it works most of the times.
Bottom Line, Minor problems are not always a deal breaker as long as you calculate the extent of the minor problem and account for the cost of the repair before you make the deal.