I have an '89 260e and '95 C220 each purchased for $500, so welcome to the club. I might have missed what other Benzes you have, but didn't see any in your profile, so I'm not sure how handy you are. Anyway, I went over both cars and put together a list of maintenance and repair items and then took them to an indy shop and for $100 they go over my list and see if they can add or subtract anything. Then I have a list of what needs done and can triage my way thru addressing hopefully any and all problems. Yeah Benzes can be expensive, but an organized approach with some outside help can cut the cost down a bunch.