While a worth while experiment, you are still going to have a hard time getting a comparable result set. You have records left over... presumably all the ones that the first batch of shoppers didn't want. You are also targeting a local set of people... hundreds of which already attended your sale and have picked up the records they wanted. If your next sale is solely advertised on, say, Craigslist, I would not be surprised if your take was much less than $10k. But I would not necessarily blame that on Craigslist when those other factors are just as likely to affect a second Facebook advertised sale as well.