Does each team member have to buy a market place item if its the same game ?
Take a look at the FAQ:
“All content sold on the Marketplace is licensed to the buyer (who may be either an individual or company) for the lifetime right to use the content in developing an unlimited number of products and in shipping those products. The buyer is also licensed to make the content available to employees and contractors for the sole purpose of contributing to products controlled by the buyer.”
https://www.unrealengine/marketplace/marketplace-business-terms-faq 
How do I give it to the rest of my team then
copy/paste?
Revision control systems maybe? Private Dropbox (or similar cloud systems)? Email if they’re small enough? So long as you can guarantee (as much as is reasonable) that only the intended recipients will receive them it’s up to you.
I did not know I could get the items off the engine, what folder would they be located in?
You should be abel to find everything in the content folder (documents-projects-your project/marketplace project - content) -> they are ordinary uasset files
I guess Epic thinks that you all use the same Account…