they have to be cheap so people will go but not too cheap people will stay at home if we get spanked on the away leg.
Agree.
Personally, I would buy a ticket no matter what the price is. I would be a bit miffed if I had to pay anything above $50 though, and I'm sure that there are plenty of people who would be interested in attending but wouldn't pay over $50.
$40 seems like a good compromise.