buy up 78/79s for under 5500, roll them into the 80-81 set. put any low value cards into the team builder sets and break even on them. you will get a lot of high value 80s and 81s that will make you a lot of coin. i already got engram, njoku, and purdy in the 12 i did today. also got a dj reader, jimmie ward, jeffrery simmons and 6 80s a couple of which still sold for 28k. it seems its about 50/50 if you get 80 or 81 and you don't lose anything even when you miss since you can roll them into ronnie harrisons or whatever. just go team by team on 75-79 filter and look for any 78/79 under 5500.
edit, reason i post this is bc i'm up to 7m coins and going to take a break from the coin grind.