Should it make any difference?
Why would you pay more than you have too?
Its the company and competition that is setting the prices in the market and if the flight is full service across all fares then they should be able to expect a reasonable service standard. That is the game.
Why would you act like the company is a charity and pay more unless of course it really is a basket case?
You can always have a bad Cabin crew day. I've had some doozies and most have been on QF. Next day they are all fantastic.