You are a student pilot right? If so just look at the VFR stuff.
VFR charts:
Sectionals are ~$8 wherever you go (in person, else you pay shipping). I have never seen this price fluctate (exception: I have seen them cheaper at EAA OSH during the airshow but you can pick up all sorts of stuff dirt cheap there). Sometimes I fly to a nearby state with better sales tax to pick them up but they don't change at all. There is only 1 maker of these charts (NOAA/FAA). These are needed for ALL flight students. It expires ever 6 months. You are alright getting this before you go flying but it won't kill you to go flying without it for the first few flights.
Terminal Area charts are $4 (I think) in person. Again, the price doesn't really fluxuate. Again, if you want to pick it up cheaper you could pick it up at a nearby state for less sales tax. There is only 1 maker of these charts (NOAA/FAA). These are only needed if you fly near a busy airport (prob class B only but there may be a few Class C's that use these). It expires ever 6 months.
An Airport-Facility Directory (aka: AFD) is $4.50 (or so). There is only 1 maker of these charts (NOS/FAA). It expires ever 56 days. Don't get one till your CFI tells you that you need one.
The only way you could get a subscription to these is if you buy through an online retailer. I wouldn't bother because realistically you don't need to update them as soon as they expire. A sectional might be the only useful updated chart you worry about flying with and that only needs to be bought twice a year (AFD should be bought once or twice a year and a Terminal Area chart is totally useless unless you fly alot in the area). FBO's won't try to rip you off because if word got out that there was a cheaper place to buy the charts, they wouldn't do any business any longer (a 15 minute stop at another FBO for cheap maps on a cross country costs ya nearly nothing).
IFR:
If you aren't in IFR training, these won't do you any good and thus don't bother.
Here you have a choice between the Jepp charts and the NOS charts. Both expire at the same time. Jepp is more expensive but also has the advantage of being released for the whole world (you could get Canada charts if you wanted) and are used my most airlines and commercial operators. The NOS charts are much cheaper but only are released for the US only.
Jepp charts vary in price a little from FBO to FBO but it is usually only $5. A subscription to Jepp costs ~$300 for a year.
NOS you just buy when you need them (or are running low on $$$)
Either way, your CFII might have a prefrance and/or have some helpful advice.
I am not used to these forums. I am used to ezboard, proboards, and phpbb.
