looking for recommendations.

Any tips on where to find cheap bras? I'm getting a breast reduction soon, and would like to buy really, really cheap ones to show my surgeon. I tend to stay out of the undergrounds shops because, 1. the shop owners always look at my chest and do that hand waving motion to indicate that I cannot fit into their products lol (even when I tell them my situation in Korean), 2. shop owners are pushy/annoying/hover, and I really don't feel like repeating, "그냥 구경 중이에요/그냥 좀 둘러보려고요." 1,000 times. I was thinking about checking out HomePlus (I haven't shopped there in about five years), but I'm in Gangnam and don't want to make the trip to Jamsil if I can help it. Please and thank you!