I think a lot of people know that the gains are pretty bad from these boosters, but not exactly HOW bad.
Well let me tell you how bad it actually is:
You gain 12 points per minute.
There are 60 minutes in 1 hour. 
The max boost is 18 hours.
12x60x18= 12.960
So yeah, you pay 4,50 (euro) for 12.960 bonus credits, and that is WITH a sale going on.
A merc is 50.000 points, or 9,99.
Do I really need to do any more math for you guys? 
Let me add a little sidenote that you do gain double points in competitive matchmaking, but that is currently in such a horrible state itâs no fun for anyone.