Interesting experience at Greenhills last weekend. I wanted some shorts and tops for the gym and was told Greenhills was the place so I went. I noticed most stalls dont have prices listed.
I picked up a pair of Nike shorts, obvious fakes but hey they'll do. Was told they were 400P which is only about $10 so I bought two pairs.
I was walking in my neighbourhood and saw a stall in a similar mall selling the exact same shorts for 100P! My Filipino GF said most foreigners will be charged double so I learnt a valuable lesson!
BTW - if you're looking for fake Adidas/ Nike sporting gear this stall in the Pavillion Mall which is a smaller Mall located near the Megamall sells tops and shorts for Protected content which is SOOOOO cheap!
They also have XXL and XXXL so you should find something that will fit.