The third quarter reports from Hamptons real estate brokers are in. The number of sales jumped 31% from Q3 of 2012. The median sales price was slightly higher than a year ago, while the average sales price dipped from the same time in 2012 because of a shift to lower-priced sales. Sales below $1M expanded to be 64% of the market, probably driven by the spike in mortgage interest rates in the spring. The number of sales above $5M jumped 53%, however. Inventory increased 27%. If the trend to greater inventory holds through the fourth quarter, further increases in prices could be stymied.