where are you mate? You may find clearing the ecu code memory or scanning the abs controller (if its obd2 96>) will get rid of or confirm the reason for the abs light, an exhaust can be had from ebay for a reasonable price, starter motor and power steering pump too, but the mot is the thing until you know what it needs.
Kwik-fit do mots......and are cheap. Chuck it in to see what they reckon, and they will do a free brake check too - dont need to buy owt off them, just get the free check!
Maybe a member near you could scan teh car with a vag405 or vagcom for you, after that its down to the mot I reckon, if it comes out wi a pile of fails then maybe rethink that particular car, but it depends on how far you would go to have the mk3....rust is starting to have a lot of them now and welding is common at mot time, as are brakes, exhaust, cv boots, lower arm bushes, etc on mk3's and there can be more, get it checked for a pre mot and see what that brings then decide.