1998 Forester Oil leak...

Hello all! I have a 98 Forester, with just below 100,000 miles, and have been having an oil leak for a few months now. It started as a slow drip (one or two spots on the garage floor every couple of days, to now where there are a few drops every day, and now a sizeable stain. I have read and heard on here and from other Forester owners that the head gaskets blow and engine blocks crack prematurely on the Foresters of that vintage. How much is this going to cost me to repair? I imagine there are a lot of you with that have gone through this already. I like the Forester and all has been pretty good about it, but I find it rather disturbing to have such widespread problems with head gaskets and cracked engine blocks before 100,000 miles. Thanks for any information!