Many times big box stores will sell them as an annual in many eastern states.
You can check locally to see if it holds true in your area
There are some on Craigslist in your area..... cost varies.... average cost is 5-20 bucks across craigslist nationwide, the average is even less in southern banana friendly states.
Real time listings...
san antonio farm & garden "banana" - craigslist
treasure coast farm & garden "banana" - craigslist