I'm not even in the game, so take this with a grain of salt.
I don't think selling your beats is going to get you anywhere. It's small time. Small time thinking, small time results. Too much thinking about getting paid today & no vision of the future.
It is a business, it is your product & you need to have as much control of how that product is distributed & presented to the public. If you sell your beats, you're giving up control to the rapper to do with it as he wishes. If you're not working with the artist to develop the finished product, you're not much of a producer, your the talent. The drummer, if you will.
You need to focus on building a crew, like NWA, like the Wu-Tang Clan, like public enemy, like the Neptunes. Find a group of artist, form a partnership with them, collaborate with them, promote them (or form a partnership with a promoter). Figure out the money thing up front & make sure everyone agrees. If no money is coming in (say a mixtape freely distributed) no one gets paid. If you've got a group getting paid to do a show, everyone involved gets a cut (figure the cuts out up front; 10% for you, 5% for the promoter, 10% for future investment, 50% for the performer(s) or something similar).
The goal is a record contract. At first, you're going to get what you can get & make the most out of it. As you get better at your craft, target better artist, target a better promoter, drop dead weight, even pick up other producers. If you are who you think you are, if your work ethic & talent is all that, you'll blow up, your crew will blow up.
Either way, there's more of a future there, than selling beats.