There are no contracts, but there may be monthly fees, depending on how large of a Market shop you want to run.
We wanted costs to be predictable for our users, so we opted for a flat rate subscription model instead of a percentage-based fee on each sale.
We do offer a 'Free' subscription option, which will let users set up shop, and get used to things without any commitments or monthly fees.
We have recently increased the number of listings from 5 to 15 with the Free plan.
You are free to move your shop between plans, and can cancel at any time.