I built My boy a wheel.
I'm going to build each of my girls wheels soon too.
It's made from the same Cake plate (or looks to be) as Reapers.
I used an old pair of rollerblades that was given to me, and the whole thing cost $13.
I did end up taking the base off because I didn't like it, it was too big.
I mounted the wheel to his cage and he loves it that way.
If I had known that I wasn't going to use the base and just made it to go on his cage it would of only cost about $7.
He had NEVER used a wheel before I made this one, (and I had tried)
He started off just walking on it, and now he runs on it for hours every night!
I'm not saying Reapers are bad or anything. I've heard he makes them with high quality products.
But it will give you some ideas/options.
especially cost wise, I know I can't afford $40+ on a wheel.