Item shop idea

Simple idea and almost no coding needed. My idea is that we should have a /trades command as a shop or an NPC labeled (Trader)
At this NPC (or with the command) it will open a list of items for sale. Any player will be allowed to put an item for sale in this shop with a set price.
Non-ranked player can set a limit of 1 item space for sale (even if its a stack of x64) with a maximum price of $20,000 per sale.
VIP+ player can set a limit of 2 item spaces for sale with a maximum price of $40,000
MVP+ player can set a limit of 4 item spaces for sale with a maximum price of $70,000 total
ELITE+ player can set a limit of 8 item spaces for sale with no limit of price ranges.
Items that can be put into the player trade/shop can be any item that a bandit can hold in their inventory (sheriff armor and weapons will not be available)
The main benefits of this system would be to prevent scams, add more ways for people to easily buy and sell items they may not normally know people have available and even introduce a new twist to the game-mode we all love.
Give your thoughts, suggestions, and please give reasons to yes or no's!
Thank you!
- Meepism