JMT reminded me of something I seen in Main Street Station. I never played it, so I have no idea of how it worked...but...
Do you find penny machines a little pricey? I little too rich for your Las vegas gambling budget? Well, we have an answer....that's right now there are 1/2 cent machines.
Now I'm sure playing max coins still comes out to something like $4.50 per button push, but it's only a half penny!
BTW, what does a half penny look like??? I don't beleive the US currency has one of those? Hmmm, I wonder what happens when you cash out and only have a half cent credit???? Think about it!