What expenses are required to build an app using Bubble.io?
Hey @jessehilton612 
Welcome to the Bubble Community! 
It depends on how much you are going to build it on your own. You can build a lot on your own with the free plan and then when you want to deploy it you can start with the smallest plan which is something like $30/month. If you want someone to build it for you, then it depends on the size and complexity of your app. 
Hope that helps a bit.