It's a little drive but you won't get a better price than fire extinguisher shop in battle creek. They do both of my C02 tanks and my Nitrogen tank. 5 pound c02 refill is $12 and 10 pounds is $15. You can also buy tanks from them for much less than you probably paid for your aluminum I bought my aluminum online for about 90 I bought a 10 pound tank from them which they built out of an old fire extinguisher for $40, filled. I bought a 40# nitrogen tank filled for $75 a few years back, being I only have one nitrogen faucet that should last me the rest of my life.
I put the address below you're not too far from Arcadia ales in Battle Creek so get some gas and have a pint.
They keep strict hours. Closed at 4pm and always closed between 12:00-1:00 for lunch.
120 Service Street
Battle Creek‎ MI‎ 49037-2395
United States of America
(269) 963-3233