Feeder cards mucho needed

Hey gms another thing that I know is on everyone's mind but I haven't seen a thread is feeder cards. Long story short we need more of them. I'm at the point where I wanna buy more packs but it's counter intuitive because I have about 22 sr cards currently all equipped but unleveled (dumping all my feeders into the two ur I'm trying to level) can you make some way for us to get more c and r feeders? Maybe a tradein program or something? 1r=3c 1sr=10c kinda thing? Just a thought cause you would totally get more of our money this way
Thanks again for having this forum and listening to our feedback