Re: how much will cost me? So they dont overcharge me!!
Just getting the exhaust bellows replaced was going to cost me about $700.
In all fairness, on an alpha1 gen1 getting everything diss-assembled to the point of replacing the exhaust bellows was a major PITA. Partially due to lack of tools.
To do the job yourself you'll need an engine alignment tool, gimbal bearing install tool, rent a bearing puller (free) from an auto parts store - although the smallest one at autozone wouldn't fit in my bearing, the $10 one from murrays did though - and a tool to fit in the gimbal bolts (or a hex key will fit, but not recommended).
$250 mentioned above is, I believe, a good estimate for doing it yourself, tools included.
Another suggestion is to replace the exhaust bellows with a tube. I didn't know better when I did mine, but the tube can be replaced a lot easier in the future than the bellows.
Do your impellor when you're got the outdrive off. Its another 5 bolts on an alpha1, might as well.