I paid $2400 for mine (2wd, low hours) a couple or three years ago, and that included a 48 inch belly mower...since then I bought a 4 ft box blade for 175 and a dirt scoop for 150...FIL gave me a plow. Bought a 5 ft rear finishing mower that needed work for $75 and rebuilt it for a couple hundred. Got steel plate from scrapyard for front weights for $10 or so...bought iron weightlifting weights for rear wheel weights for another $65 or so. So to me $3500 seems a little high.
I really like mine, I just wish it weighed another 500 lbs or so. And one day I intend to weld up a front end loader. This site
Loader Plans, CAD Plans, Build a Loader, Front End Loader - Blank Page has plans. Go through the site and there's tons of pictures, including loaders and backhoes on 1100's.