what is your price range for a case?
i am a little torn on the whole "you get what you pay for" thing. i may be fairly new to the game but so far my only real issues have been with the cheap, bottom of the barrel field paint. i was blown away at how straight and consistent Marballizers are when my friend picked up a case. There are some other ones I have read good reviews on here that are just like a step down from Marballizers in terms of price that I am interested in trying, but yeah I bought a case of 2000 Draxxus Midnight from Sports Authority for $30 (i know you said you can't use these) thinking it would just be for plinking around and test firing and was pleasantly surprised by how consistent it was. I literally didn't have a barrel break all day until I chopped one of the crap pink low grad ones in the breach and then things went downhill.
I was a bit disappointed with the Karnage Bites for the price, as they were literally no better than the $30 Midnights and I dropped $20 more for the case of Bite.
i would say, if the field supplies paint, talk to other players that are there before you buy paint from the field. ask them what they're shooting and ask if they had to buy paint at the field what it would be. if i'm reading you correctly you're just playing some rec ball. shooting top of the line balls shouldn't be a huge priority, just something consistent and decent
also, why can't you use blue or pink?