You may want to check out EBay ... sometimes they have used animal equipment for sale on there.
We have 6 flying saucers and love them. Any particular reason you do not want a flying saucer wheel?
Quality Cage's Chin Spins are made of wood ... I like the way they are made, but, I would have to question the type of wood it is made of (to make sure it is a wood that is safe for chinchillas) and also consider the fact that chinchillas love to chew wood. Depending on the chin, it could be one that would have to be replaced fairly often due to the damage made by the chewing. You also have to consider that some chins love to set and sleep in/on the exercise wheel ... chins poop, even in their sleep. They often will urinate any where they might be at the time ... wood is absorbant and hard to clean as apposed to metal.
I've been searching for a bigger wheel for my chinchilla because i had to get a substitute wheel for his last one that he broke, but this one is too small.
When it comes to chinchilla exercise wheels, it's basically ... you get what you pay for. Take the cost of the first wheel, the cost of the current 'substitute wheel' (which is, as you said, is "to small" - a wheel that is to small can cause spinal damage) and the new wheel ... are all three going to add up to less than $100? Often a good investment on the front end is worth it in the long run.
I'd save up for a good one instead of looking for a cheap one ... just my opinion.
If your chin is allowed out to run and play and has a large cage, a wheel would not be a necessity, but just an option.
Jo Ann