I got mine through a binder donation program based in the UK. I simply didn't (and don't) have the funds to purchase one, so I looked through what was available via their catalogue and got extremely lucky.
Mind you, I do have to wear layers. In just a t-shirt, it is clear that I'm carrying a lot of excess fat or whatever around my chest, but in a button down the stiffness and non clinginess of the fabric smooths things out. Top that with a vest, pullover or blazer (or combination of two of those) and I'm good to go. T-shirts and hoodies/sweaters, however, don't seem to give the same effect. So I tend to dress somewhat formally.
Thomas