Dickson Co. in Sacramento makes and sells hydraulic stern thrusters. I believe the base cost is around $5 to $6K, plus installation, of course. I think this unit can be self installed, IF, repeat IF, you are reasonable competent and maybe at least somewhat familiar with hydraulic systems. Big plus is not big hole in the transom, just small holes for bolts and hydraulic lines. My boat came with one installed in the mid-nineties, and I really like it. One plus is that, because it is hydraulic rather than electric, you can run it for any length of time without worrying about overheating, which is often a concern with electric units.