As with all markets, the trend lines is always, net, up

A book auctions monitor wonders if the market has just peaked:

We have been aware that pricing has been challenging at the low to medium price points, but, perhaps somewhat surprising is it was soft at the higher end as well. Fewer sales in the $500 and up range, and lower medians at auction houses that cater to the highest level of buyers, were reflective of this softness. Perhaps we could have foreseen this from the Top 500 prices paid at auction we published last month (click here). While the top price paid at auction doesn't tell us much about the market in general, by the time you get to the 500th most expensive item, it frequently reflects a trend at the top. After several years of rising, the price of number 500 declined from $79,800 to $74,200, or the same percentage as the decline in the overall median price – 7%.