A local goldwing rider has his nuvi mounted using the suction cup to the windshield (or some other smooth part). So far he's been lucky, and swears by it. I think his logic is flawed, and will be rubbing it in, "I told you so", after it falls off.
I think a cheap ram mount can be had for under $40 for a control mount. I like the techmounts product myself. It's a bit pricey, but is better than that projectk product offered elsewhere - unless the latter now offers angle adjustment too. If you go with the techmount, see about getting the rectangular plate and the quick release adapter. I don't believe they offer any sort of quick release yet with their round plates. This adapter uses a spring loaded pin which engages a hole on the rectangular plate. This lets you remove the gps and cradle/adapter as an assembly instead of popping it into/out of the cradle each time.