I do mark to market at the six month moving average and when I sell items for Monero, I also mark them at the six month moving average so that prices move slowly.

https://xmrbazaar.com/user/AuroraGeneralStore/

Edit: Over the past, call it 7 or 8 months. It’s increased by 29.8% ($142.50 to $184.67).

Edit 2: That obviously means that all item prices in Monero have dropped by 29.6% in the past seven or eight months.