You don't need to post all mods for FREE. If you worked hard to create the mod and it required a lot of time from you. You want to get money for it and it's normal. But some easy mods can be shared for FREE because they are not so hard to create. It's my opinion. In the same time I saw a lot of mods on Expertzzz which had about 1 line of new code and were sold with some price($10 - $20). It's only your decision to sell the mod or share it for free.

P.S. Don't forget that when you purchase Premium see more status, you get some other advantages too. Post products is only one of them.

P.P.S. Premium status is needed to post products in Market. This limition was created to protect the market from reseller and fraud like it was on Expertzzz. It you know it was a big problem. New products like 'Pay $10 and get 100 mods for Dolphin' appeared on Expertzzz very often. Boonex added this limition to protect me and you and the others members of the community, vendors from resellers and buyers from such packages, because usually buyer paid $10 or more and receive nothing. Everybody should understand it. I think $20 is not so great price if you want to start your internet business here. Also I recommend you to purchase Premium membership on 1 year if you plan to post mods continuously. ;)