It looked pretty much like any other toilet. It's a one piece, but I have no idea why it was so expensive.
Chances are you may have some rot in the joists too. If so you can treat them with JASCO TERMIN-8 wood preservative to stop the rot from spreading, then sister some new wood to the old joists. I always recommend pressure treated in this application. Same with the subfloor, use pressure treated plywood under the toilet.
Don't hesitate if you have any questions.