BMX specific shoes are worth looking into. First because they are designed for BMX and second because it puts budget back into BMX. The Vans 114s come with the BMX sole with part waffle, a designed section to absorb impact (the heel) and the middle section to provide maximum pedal grip. The Pop Cush insole provides comfort and the raised Waffle Cup BMX rubber section on the heel adds to the strength of the shoe. Kevin Peraza is one of the many Vans riders who use the 114. The Vans sprocket logo on the tongue shows you're a BMXer supporting a brand that backs BMX. Around $90 USD in the States (excl. sales tax) and roughly €100 in Europe will get you a pair. Now available in Dark Olive. Don't worry, they're also available in black.
Vans.com should lead you to a place that has them.