The issue with sets in this game is its always cheaper to just buy the player on the market. Right now it would cost me about 250k - 270k coins to build Chase Young, but he's selling for 192k.
The issue is these damn BND cards. Years back you would earn a NAT card or two from solos you could use in the set. At least in FIFA/FC they let you put the NAT cards in the sets, that way you can complete some good value sets. MUT just trys to screw you at every turn.
What EA don't seem to understand is that if you make the game more fun, the grind more rewarding, people are actually more likely to spend a bit of cash cos they feel like they are getting value. I personally am way more likely to spend some cash in FIFA/FC than MUT cos even the NAT cards are worth something.
In short, fuck EA.