I think it should NOT be here. I'll explain why.
First of all this forum is about MP. If will be marketplace, 100% that people will post less useful info( why need to write topic, if you can make ebook and sell it for few $? ), also will be tons of scammers ( even if sell from 2lvl, it's too easy to get it. )
Have seen similar forum, but about different software. Only marketplace and news section is alive at the moment( because people just stopped to write useful info, they only try to sell it). In few words nearly everybody is just selling info or he is the "mentor" ( I don't want to see it here, I like atmosphere here, like it is now ) , also hate these big colored signatures with products and million negative feedbacks( and negative feedbacks are even on good products, just because people didn't understand smth). And most interesting that for this will have responsibility only Massplanner team
Administration, need to check out every seller(and even this don't give 100% that seller is legit.) Also it takes time. Better spent this time to Massplanner
Also guys don't forget that you can ask here questions, like where to better buy this,buy this. Sure that some one will help you!