A hobby business is not a business, it's a hobby and hobbies cost money.
If you plan on this being a business you have to figure out first how much turnover you have to make to make a go of it, and if $13 / month for a bank is a make-or-break decision then I would suggest you look long and hard at whether or not this is a feasible endeavor.
For sure it is possible that you'll be doing this expense out-of-pocket for a while, but then you just put all these expenses against your future revenues.
A typical small business, including all overhead, such as administration, tax filings, equipment and so on will cost you at least $200 / month, so if your projected profits when this thing is up and running are lower than that you really should reconsider your plans.
This is not meant to demoralize you, I just think that if you doubt about spending $13/month that you have other issues than choosing the right bank.
I chose mine for reliability, easy access to international banking, the fact that my balance is insured to a serious amount and so on, the 'costs per transaction' and 'monthly fees' were the least of the considerations.
The recent crisis has born out the wisdom of that decision, by going with a large but cooperative bank they were hit very little by the affairs that caused their main competitor to now be mostly state property.