I would imagine that the wider spider (whee! a rhyme!) gives a bit more stiffness. The arms are more substantial than the ring, which would give you less flex.

To answer the OP's question, no, I don't think there are any cheapies. I've had lots of problems finding a decent 1/8" ring in 110/130. I have on order a TA ring which should do well for my beater. It's 130 bcd AND 1/8", so it should solve my problems.

If you really want a track crank, expect to pay track crank prices. There's a reason they cost as much as they do. THEY'RE WORTH IT!!!!