I've got two plugin ideas, but zero coding knowledge. Are these two ideas even possible? 1. The first is a rental plugin, similar to SimpleRegionMarket but with additional limits and a simplified interface. Rental signs can be assigned to a specific type of rental, and can have limits such as requiring a shop to purchase a warehouse. Additionally, WorldGuard's snapshot feature is used to create/backup rented properties. More details available here. 2. The second is an auction plugin, but linked to WorldGuard regions. Players can only bid inside a specified zone. Additionally, bidding is simplified via using an auction chest to sell batches of items for a single bid (instead of selling single item types). More details here.
For me it would not be difficult. It will just take a bit of time. Depends on the skill of the programmer..
Auction Plugin - http://dev.bukkit.org/server-mods/craftbay/ Not exactly what you requested, but it works fine.
1. World Edit is working on that i know but i have no clue when it will be released. 2. there is lots of auction plugins out there.