... But you have an option. Your ASHI-Approved Home Inspector should be able to help you out here. First, he does his 'normal inspection'. Then, he tells you what damage, or potential damage, there is to the home. THEN, you ask him to give you an estimate at what it would cost to FIX the problem(s). This particular problem is not normal wear-and-tear. If the estimate is $8,000 to do the fix, then talk to the homeowner about either knocking off $8,000 from the price, or working out some sort of deal where each of you pay for part of the fix, or ask that THEY pay for the fix as a condition of sale. (This is where your Attorney takes some Escrow $$$ and writes this condition into the Agreement of Sale. You DO have a Real Estate Attorney that's familiar with doing Closings, right???)
The thing that scares me about all this is that, even with the current 'fix' in place, the gutters are still clogged and the landscape is poor. What does that tell you? DO the current home owners do ANYTHING for up-keep to the house??! You also have to ask yourself ... If the gutters and downspout problems were addressed AND the landscape was 'fixed', would the current fix in the basement have been necessary in the FIRST place??! That's why I'm such a hard-butt when it comes to the Dry Basement Systems you hear about (and see in the basement.) In a lot of cases, this type of problem could actually be FIXED and NOT 'patched' as it sounds like it is in your case. For me, I'd run. I don't care what type of warranty is 'transfered' (if it can be), or not. The situation as you describe with the gutters and landscape all messed up too, what else could be 'wrong' or 'patched' in and around the home? Again, you need a professional home inspection AND an attorney. Sooooo, on face value, I'd run. Otherwise, get some professional advice and take it from there. You need some people to look after YOUR interests.