Erin-Candice, I feel your pain. I had not been doing this long, about 5 years for money, and at this point, I am still not making ends meet. Perks are a good thing. But getting transportation money does not take care of my other needs. With all the stuff that you need to get, job related materials, and if you are part of the union, dues and the likes, a stage manager is left with very little money. There are no savings that can help you while you are looking for the next job, or until your first paycheck, which depending on the contract, could be a week, or at least a month, sometimes. Perks and other stuff are ok, but right now give me MONEY. I need it, I can't make it to rehearsal if I can't afford to pay for train and bus fare. Getting a another job while working a show, sometimes is almost impossible, because stage managing is very time consuming, not to mention that your employer has to deal with the fact that you will be missing days of works once awhile, and they probably won't be pleased with that.
I say be willing to negotiate, and go for what you want. You want money?
Go for that. Actors do it all the time, why not you? Are you going to get the money that you want? Probably not, but you won't know if you don't ask.