Need opinions! 4-Plex in Great location - foundation problems

[Bobby Balow]

We found a great, recently redone 4-plex in a location that our property manager says is ideal. The sale is as is and will be our first long-distance property that we will not see before placing an offer. We found out that there are foundation issues that are estimated to cost around $18K, which isn't a total deal  breaker, but I've never dealt with foundation problems before. Can these issues come back? How likely is it that these problems might lead to other problems? We are pretty new to real-estate and haven't purchased a "fixer-upper" before. Thanks so much in advance.