You must be willing to sacrifice trophys
I am also TH7 right now with the same troop levels and I use BAM for gold farming. But with level 4 troops you have to be willing to sacrifice trophys for the cash. Also, I almost never use my entire army and most times I can get 100k gold with only using 25-50% of my troops (collector raids). I will use them all if I can get 200k+ gold.
But again, I do lose a lot of trophys and DE. So my strategy is to get close to 1400 trophys (and a good amount of DE) with Healer/Giant and then go on a BAM binge to load my gold storages. By only using part of my army I can almost be constantly attacking with zero down time. Once I've gotten the cash I need, I go back to healer/giant to refill DE and trophy count.
Rinse, lather, repeat. It works great.