I paid around $24.00 with shipping by looking for the best deal on-line.
I tried them because I had no parts supply to draw from at the time and now buy them when a project calls for a motor I do not have. I really like the Revell and Johan Hemi and try to pick them up in kits when I can.
A good friend thinks it is crazy for me to buy aftermarket stuff instead of buying kits. While I think it is crazy to stock pile kits I would never build just to get some parts.
To each his own.