Is there any solution to use k2 extra fields as a price for a shop?

I know about k2mart and k2store, but both of them use different system for pricing.

I used "CMK2Inline" on my site for simple editing and managing extra fields on K2, each k2 item has 2 or 3 extra fields that shows the price.

For a catalog you can use an extrafield.
If you are using a cart component however, the price should be set in the component (eg: K2Store/ J2Store).