Cap'n ARR and poteroo seem to offer sensible advice.
Forget the comments suggesting you are being ripped off for the moment and have a think and make a few phone calls.
Its pretty hard to determine who knows what they are talking about here some times. Take all advise with a grain of salt, and do some investigating yourself.
I have absolutely no idea what schools are charging these days. Phone a few see what they offer.
Solo hours required x solo rate + Dual hours required x Dual rate = ? divide this amount by the toatl hours and you will get a rough idea of how two companies compare.
Do they all charge for briefings?
Determine if there are any other extra charges that could affect either organisation.
Consider the benifits of paying dual for your training.
IF your instructor is paid for the whole time you are flying up to GFPT, he will likely be a more content instructor(maybe not).
If he is only paid whilst he flies, i.e. when you are dual, he could conceivably spend more time dual, = more $$$ out of your pocket and more in his. This is possibly more likely to happen if you are only charged at the solo rate.
You need to do some home work and ask some questions.
At the end of the day, its the quality of the training that will save you $$$ and enable you to enjoy your flying, even if it costs you a few extra $$/hr.