If you are not going to be able to enjoy your cruise because you think something else would have been better, then you should cancel and book a trip that you will be happy with.
Going over budget is a personal matter. We have an overall vacation budget and will never exceed it others are happy to borrow to fund a trip; one is not better then the other so long as you are comfortable with your decision and can pay your bills.
Someone on here posted wise words to the effect the $400 price difference means different things to different people. For some it would mean you couldn't make a payment on your car, for some it would mean they could only buy one pair of shoes next month. Only you know what you would be comfortable with.
A balcony with the beverage upgrade would be hard not to enjoy on any ship in my opinion, but we go for inside with basic drinks package and the mindset that if we don't have a good time it is our own fault.