Who is the manufacturer, and what is the model name/number of those $15 PAR38s?
PAR type photometrics are pretty easy to hit with LEDs, since the LED dice are inherently anisotropic in output. For light pattern/beam spread it's better to them to a 60W PAR38 halogen, which is an output simply not achievable with CFL technology, which is better suited to flood-lamp type applications. Getting wider spread flood-lamp type output with LEDs is more difficult to achieve without losing efficiency to the diffusers, but several vendors have decent LED floods out there that are still north of 50lumens/watt (typical CFL-flood efficiency.)
Costco has had similar deals on the ~12W CREE LR6 (R30 flood with integrated trim). The big orange box store seems to stock the ~10W CREE CR6 (very similar to the LR6, but slightly lower power & luminosity) for ~$25 regularly in my neighborhood, and they look great, dim nicely.