Originally Posted by manicmike

You're missing the hint vmaniqui. There are a million variables to how much something will sell for (where you live, condition, demand, supply), but the only one that determines how much it's worth is how much someone's prepared to pay. We all do research and learn this, and we'd encourage you to do the same. The 66 cost a lot more than $45 when it was new and will outperform a plastic sewing machine in stitch quality and longevity. However, not that many people are prepared to buy one, so the plastic ones usually go for more money. If you buy an old machine you'll be adopting it. You'll love and enjoy it for a long time and you probably won't even remember how much it was.
It's in nice shape and is a side clamping model, so I would pay $45 for it. Then again I have some spare motor/lights hanging around waiting to go on such a machine. I imagine it would be more of a hassle for you as a newbie to source a motor and light.
If I were asked for advice (and I believe we are), your first old sewing machine should be complete and working, and this one isn't complete. Just because the crank turns doesn't mean it's working either.

EDIT: I see you posted the Spartan, too. If it's complete and it feels right (this is really important) pay $30 and take it home. I had one of these and didn't really like it, but they're quite a good machine.