I've used the Garmin 76, same size, and did a nice job.. I mounted mine on a handle bar, eventually I downgraded to a Garmin ETREX, easier to use, but no channel markers on the screen, part of the decision was based on the fact that my ride buddy put a 4" color Garmin on his glove compartment lid, so I didn't need the 76, and I had never learned to program it anyway
my buddy programs in our route, and has them saved, and it has bailed us out on a couple of occasions when riding in new area's.
to answer spx's question, when I sold my 76 (older, B&W version of this model) It sold for like $70 shipped. I'd expect the newer, color versions to be twice that.
In general, I had good luck with the 3m sticky mounts when I started using a gopro and a small gps, never used suction cups myself, when I changed ski's and had aftermarket handlebars with some free space on them, I switched to RAM mounts, which are tough as nails. I personally recommend that anybody that decides to mount a gps or camera to use a mount that is custom for your model, vs a generic mount, that way you won't lose a valuable piece of electronics because of a substandard mount.