@Edent IMO there are 2 ways to think about it to make it more palatable:

• The profit enables you to do the next thing - i.e. people are contributing towards the next fun thing you'll do (which might be beers that night)

• Give a predetermined %age of the "profit" to a cause that means something to you

Either one allows you to charge a markup and therefore not undercut someone who does rely on profitable prices for an income, whilst continuing to enjoy what you're doing