3d puzzles

Hey guys,

I have a couple of really cool puzzle designs that are printable.
And I'm thinking of opening an online shop to sell just the designs.

What price would be reasonable for a game/art design?

And would you ever Buy a design?
And if so, what price would you pay for a relatively simple design?
What would you be willing to pay for an intricate design?

I know thingiverse is awesome, and open source is the way to go.

Though currently I'm a poor college student who's playing around with some 3d designs
Trying to see if I can earn some extra money here and there.

Thanks your help guys,
-Tom