sfm,
They are not really all that hard to install yourself. I did mine completely by myself with a borrowed engine hoist to lift the heavy parts. I do not recommend doing it alone - possible, but difficult. With a couple of buddies, it's an easy job.
When I checked around, installation prices were around $900. Ridiculous for a $2,000 lift. A google search will give you a few firms that will do it. However, if I was looking for someone to do it for me, I would just hire a couple of semi-strong guys that can read directions (or supervise them myself). It's just not that complex a job. Even with a couple of guys, you will likely need an engine hoist or something. The ramp with the hydraulic cylinder will weigh 300lbs or more.
Let me know if you want more thoughts on doing it yourself.
- LIONDOG