The C177 may share the same airfoil as the C210, but aside from the cantilever design it is a VERY different wing! The C177 wing is smaller, lighter, it has less fuel capacity, and it has smaller flaps and different ailerons.
$36K for a new strut sounds about right. You would have to order it, then Cessna or whomever still does parts support will have to get the tooling out of storage and MAKE a new strut, special order. Since there are very few C177RG's in service they do not manufacture a bunch of replacement struts and put them into an inventory. Companies have to pay inventory taxes so it is not cost effective for them. Most owners will look around boneyards for still-servicable parts before they will go to the expense of a new strut, or they will conclude it is time to sell the old airplane for parts.
Cessna made very stout fixed landing gear for their single engine airplanes, but the retractable gear on Cessnas has always been their Achilles' heel. They are complex, relatively fragile, expensive to maintain, and subject to failure from normal wear and tear. This I think is partly why Cessna no longer makes retractable gear piston airplanes.
RC
