Become a RE agent in Missouri

[Dyami Pike]

So I'm looking into getting my real estate agent license, and I have some questions. I don't want to be a realtor, Im just looking to access the MLS and make offers myself without bugging my agent, and save the commission.

are there running costs for being an agent?

Do I have to work for a brokerage?

Does it cost to keep my license? 

just not sure what the actual cost is after I get my license and if it would actually be worth it.