You are going to do a home inspection before you purchase the home, right? That will give you an excellent idea what needs to be fixed. The other thing is, look very carefully at the seller's disclosures. It should tell you which items are reaching the end of their natural life so that you can expect to have to fix or replace those items in relatively short order.
The other thing you could consider is a home warranty. I doubt the owner would pay for it, but sometimes you can get the bank to do it. And even if you can't get either one to pay it may be worthwhile to pay for it yourself. A home warranty insures all the major systems,. including appliances, for the home for a period of one year. If anything breaks down you only have to pay the deductible. It's also usually renewable at the end of the first year. Talk to your realtor and see what they think. I always recommend a home warranty because they are so cost effective and they eliminate an awful lot of home inspection issues since the items are covered under the warranty.