Well Brandon, although my 126 is a 560, I'd also check for the radiator neck's condition. I got mine without inspecting it myself and luckily I was gonna replace it anyway and when I removed the hose to do so, I noticed that the PO (probably the one before the person I bought it from) moved the hose up closer after the neck broke so that it would still work.Luckily I was going to replace it anyway.
Also, I don't think that the person absolutely HAS to get rid of the car because of repairs it needs. In my case, the owner couldn't afford to crash it because she didn't feel comfortable driving such a big car since all she's used to is compacts (her husband bought it for her as an anniversary gift and she was sooo stressed trying to manuever it). Other issues she had was the gas she used because again, she nor her husband had a clue about keeping the leadfoot syndrome to a minimum (especially in town & on hills where they lived-lots of hills where they live)
Needless to say, her husband got her a Range Rover (an even worse gas guzzler-go figure) because she wanted to "ride high"
She's got almost 224k on her now and has purred like a kitten and although I've replaced things like the radiator, cold start injector, coil, and plugs,etc and some other engine compartment parts, that was because I wanted to and did it as preventive maint. I change my oil about every 2500 miles which coincides with another mshop member Larry Bible who says,"change it hot and change it often".The only thing that I HAD to "fix" was a $14 switch for my pass rear window because the switch light was out on the console and just this weekend a $20 coolant expansion tank.
Not bad for a 16 yr old car with so many miles. The car's near future will see a new timing chain and rails (although was changed at 178k) for her and a new Euro spec engine to be delivered from Metric Motors to be an "extra" engine waiting its turn to go into her (unless I find another 560 or even a 420 to drop it into... IMHO I think that if the car is pretty decent, $2500 or lower if you can get him down isn't a bad deal for it if you think its worth putting the TLC into it. I got all kinds of paperwork with my 560 but even with the meticulous documentation of what the PO before the folks I purchased it from had, it failed to mention that the neck was broken and only had on one of the pages a question from the MB tech that read: slight coolant leak, "is radiator neck broken?" My thought was if the damn tech thought it may have been broken, why didn't he just unscrew the clamp and look and then advise the customer of his findings-the 2 extra minutes it would've taken him was too much I guess.
Anyway, you'll probably be alright because they are some pretty good engines (if taken care of) and you may be rolling the dice on this one, but from the time YOU take delivery, YOU have to change the maintanence regimine of the car to reflect the care it deserves if it wasn't cared for previously. Kind of reminds me of taking in a stray dog that was abused all its life... It doesn't know how to act at first because its not used to receiving love until it is showered with it and eventually comes to know who cares about it and in turn gives the same love back even if it means giving its life to its owner!