what pipe for the exhaust to replace?...you could be a cheapo and get one from a junkyard that looks in good condition and get both gaskets and install it yourself (should take an hour or 2 depending on your level of experience)

as for ball joints and wheel bearings...you have to choose between a collapesed front suspension or a hub locking up causing that wheel to completely lock up...you could get replacement hubs and a ball joint from the auto parts store and have a normal mechanic install them instead (pay less in labor and parts)...moog makes good oem replacement ball joints...however...when i did my ball joints and hubs i did the complete front suspension (but my car had some 300k miles on it when i bought it)