Prices for high level level items such as Fall or Holiday tools vary a lot depending on what time you are online. Sometimes you can buy/sell them for less than a mil and sometimes its over 3 mil. A solution to this problem would be the high level Auction house. This would prevent low level players from selling thier tools and promoting a healthy market/community for players that have invested a lot of time into the server. I would recommend around 72 or even higher.
To make the shop have items that actually matters I would have a filter that excludes noncrate items. It would make sense since we would at worst have vote items which are still pretty good tools. Minium price I would set at like 50k+.
I'm not sure exactly what the plugin allows, but I'm sure you could figure something out.
+ Promotes trading between players
+ Set clearer prices for tools
+ Way to regulate money easier with tax (optional)
+ Make donated content more valuable since it probably would sell for more than it does now
- Takes work to create