Wow, last time I had one filled was 2 years ago and it cost me $40 - and that wasn't from empty. After that, I never bothered going back. I think it was close to $3/lb
The other part is - the only place in town that fills is Tractor Supply. That means you have to go in and stand in line at the register, because that's the only visible employee. Then you tell them you need a tank filled. If you're lucky, they understand what you mean. If not, you have to explain that the do, indeed, fill tanks there.
Once they are convinced, then they have to call in the back to find 'Gus' - since he is the only one that is checked out on filling the tanks. Problem is, even the people in the back don't know where Gus went. Maybe he's on break? Oh, he did say something about going to lunch... but it seems like that was a while ago... let me go look....
Eventually, Gus is located, then you have to go meet him by the big tank. He grunts at your tank and suggests you go to Home Depot and exchange it the next time you need a refill.
Gus sighs a few times, then decides to go ahead and fill the tank. Now you have to go back inside to pay. And they say, "Oh, didn't Gus show up? Let me go find him..."
"No, no, no... Gus filled it, I just need to pay..."
"Okay, that'll be $40" ugh
The Home Depot used to be easy - it was a self-serve exchange. Took me about 8 minutes round trip. Now you have to go inside to pay for the swap first. It's also a challenge trying to find someone in there that knows the SKU for 'tank swap' so they can ring you up.