craigslist needs an auction

i have a lot of the kit from my R/C airplane days. Im trying to unload it on craigslist. The crown jewel - the radio and servos were put up for $80. Noone replied. Im reposting again at a lower price but how low do I go? I could reduce the price a little but i could still be waiting a week to learn that price is too high. Basically I need an auction. I use craigslist because closing the deal involves no shipping. if its a good price it usually sells in about 3 hours. the buyer often comes to my house the same day. thats the part i like about craigslist. add an auction with a buy-it-now price and that would be great.