The prices on the motor mounts are outrageous. The front, passenger side, and rear ones run about $300.00 each :blink:, and the driver side one (under the battery) costs $130.00. The passenger side and rear ones are liquid-filled hydraulic mounts, so that may be why they cost so much, but the other ones are just rubber and metal...
As for the cost of replacement, I was given a quote by my local mechanic of $2100 for parts and labor...ouch! I didn't think it would be too hard to do it myself, so I decided to buy the parts. I check all around before buying mine, but I ended up having to go directly to my local Mazda dealership. None of the chain stores had them.
The front one was the easiest to change, then the passenger side, driver side, and finally the rear one. The first three each took less than an hour to change, but the rear mount must have been why my mechanic's quote was so high. Had to disassemble the freakin' exhaust system, then all the bolts were so tight. What caused the most trouble was the lack of space to work in. I had to keep taking things off just to fit my tools in the ultra-tight space. Six hours and a few scraped knuckles later, it was finally done.
Actually, you may be able to get by without changing the rear mount. I left that one for last, and I didn't notice any difference at all once I changed it. It was definitely broken because all the liquid was dripping out of it, but as far as I can tell, it is only stressed when you are in reverse. The rest of the time, the engine is pushing on top of it. Unfortunately, you cannot see if the mount is broken when it's installed because it's covered up by a heat shield. Good luck on getting your mounts fixed.