How accurate is their pricer if you just use their default #s? Also, looks like it's not in real time. Any thoughts?
What does "accurate" mean? Do you mean if you plug in the IV (computed from the price at which the market is currently trading), will it return the price at which the market is currently trading? Do you mean will it successfully predict the correct theoretical value of an option even when the market is trading elsewhere?
I guess my point is, how would you know? If their model were broken (which seems highly unlikely), it will be reporting a broken IV. If you plug that broken IV back into the broken model, it will almost certainly return the price it computed the IV from in the first place. Make sure you're using the right model--equity or future? american or european? Risk Free rate correct?