I happen to work in electronic payment processing, so think about it a lot. Here are a few notes about it all.

Above all, it's valuable to let people pay however they want. Just like you want to be able to dance with whoever you see next in your line, you want that random person to come to your dance at all. If someone offers you a left-handed handshake, you pretty much always accept it; they probably have a reason, and even if they don't, why spoil their joy. Increasingly, it's just expected to be able to transfer money electronically. All the craft fairs are accepting electronic. I was even at a tractor pull recently, in the deep country, and the food stand accepted Cash App in exchange for a BBQ sandwich. All aside from any argument of dollars and cents, it's just a courtesy to go to small efforts for attendees.

That aside, let's geek out a little.

Cash payments are beautifully simple when they work. Especially for smaller, simpler dances, there's something lovely about taking a collection and then dividing it up before everyone goes home. There are deep-seated reasons why much of social activity consists of exchanging little tokens with each other.

Cash isn't as convenient as it used to be, though, especially for an attendee. It's not surprising when someone forgets to go to the ATM before a dance. Also, it's mechanically faster to slide or tap a credit card than to count out the tokens.

For someone wanting to dip their toes into electronic payment, the easiest way to get started is a peer-to-peer service like Cash App or Venmo. Seth, your poster is most excellent. Those apps will act like money jars, where customers put in money with their phone and you either monitor the payments on your own phone, or just accept it on the honor system. Square will do better for you, but takes more setup. It will track "orders" for you, rather than just the list of payments that have happened. For example, it can tell you if a given $10 payment was for one full admission or two college-rate; it can certainly tell you which orders happened at each location. It can also help you with add-on stuff like gift cards (best present for a dancer who has everything) and with loyalty programs (come 8 times, get the 9th dance free). Square can also give you cheap hardware to accept credit cards with.

To the question on tracking your payments, I believe pretty much any software should be able to tell you how much you made tonight, on the spot. You won't get the money for 1-3 days (the financial system is a rube goldberg machine), but you'll know how much is coming.

3% differences eat at my brain, too, because they are *almost* zero, but not quite. I think the charges are not really enough to worry about, though. Cash isn't as free as it seems and may be even more expensive, just in less obvious ways. Cash has costs once you deal with things like: the risk of handling it incorrectly on a given sale; the hassles of making change and sometimes not being able to; and the ever-present risk for some of the money to disappear off the top. Most importantly, though, 3% isn't important if you get an occasional extra admission once in a while. Which gets back to the first point.