I believe that the funds raised from the sale of merchandise at The Orange Blaze Mercantile supports the efforts of the FTA. $5.00 for a map is acceptable in my opinion, especially in that it will make my hiking experience more enjoyable in more than one way. First you get a quality map, and then trails are maintained, aquired, protected, and supported. That's a pretty good return on $5.00.
There are several sites you might check out that while they do not specifically cater to the FT if you know your maps you can utilize them very effectively. Below are a few that come to mind...
http://www.topozone.com/http://terraserver-usa.com/http://maps.google.com/ If you can use other online resources like local forestry maps, and park guides, the above maps help greatly. I've found that most brochures and websites will mark the FT on there map, although sometimes not very well.
Hope that helps just a little!