another suggestion, depending on how cheap you really are....

SCCA does not mandate SFI rated shoes, most of the super high end shoe makers manufacture the same shoe in an SFI rated and non SFI for use in karts...as long as the shoes are leather and not plastic they are legal for use....myself, I'm not real comfortable with that so mine are fire proof but there is nothing in the GCR that says they have to be.