Negotiating on school fees? Tread gingerly.
There are two types of negotiations.
One is where a student, or prospective student wants to train, and sees the fees as reasonable, but can't quite afford the whole thing. In those cases, I don't see any problem with someone asking for a temporary reduction (until things get better financially), as long as they make it up in the end.
This doesn't necessarily mean that they have to pay all of the money owed, but rather, that they can find ways to pay back the dojo in ways that aren't monetary. For example, someone who is a certified CPR instructor can offer to certify your staff in exchange for part of the tuition owed, or someone who makes signs and banners can put his craft to work for the dojo in a similar kind of exchange.
The other type of negotiating, though, tends to come forth as more of an insult to the school owner. When a prospective student insists that the programs aren't worth the money, and demand a significantly lower tuition rate, without offering to make up the difference, it's really not worth signing him up. Unfortunately, often times, these kinds of students don't see the value in your program, and are more likely to run afoul of the financial matters.
The way I see it, let such people find a school elsewhere. If I were a car dealer, and sold brand new Honda Accord sedans for $19,000, and someone came in demanding that they only pay $13,000, I'd ask them to go shop elsewhere. If the usual people stop coming into the hypothetical dealership because they think my prices are too high, then I'll make adjustments, since dollar figures will do the speaking correctly.
Do such people have legitimate complaints? Maybe so... After all, if a school is charging 300 dollars a month (yes, there are schools that do so), and if the programs are full of fluff and no substance, then they do have a point. However, if they don't like such schools, then they should simply not go to them.
Those are privately owned businesses, and how they conduct their business is the choice of the owner, not the students. Those who disagree can simply speak with their wallets, and not sign up.