This is a special piece - it looks like the bottom row of a Stone Pagoda, and it even tiles properly with Stone Pagoda blocks. The trick is, it won't tile with the ones below it. Use it to put a roof in the middle of your pagoda! Kind of a key feature of pagodas, right? It will also tile with Decorative Roof Dragons.
Stone Pagoda Base price in Growtopia: sells for about 65 WL (median of 1 offers from community Discords, past 30 days). Live price chart and the latest buy and sell offers.
Recently sold at: UIXL, VEVUV, A6EZ