The D7100 is three years newer than the 7D. A better comparison for the D7100 will be Canons 70D when its announced.
Bodies: 6D, EOS-M with EF-M 22 2.0 lens
Lenses: Rokinon 14mm 2.8, Canon 50mm 1.4, 85mm 1.8, 100mm 2.8L IS Macro, 135mm 2.0L, 24-70mm 2.8L II, 70-200mm 2.8L IS II, Extender EF 2x III
Speedlites 90EX, 430EXII, 600EX