If you have a Kmart near you it may be worth a look there. I found a cheap little crop top style that came in a 2 pack, it was quite soft with sides that were higher than normal and ended up being more comfortable than the surgical bra. I didn't have the leakage but felt more comfortable with pressure applied to the wound - presuming your incision site is around the same place as mine.
Plan b suggestion have you tried to find a boob tube style bra, if you put it over your proper bra you may be able to lift it high enough to sit under your armpit and it should be firm enough to hold your dressing or the pad.
That is as creative as I can get right now, good luck.
