$400 per map is cheap...
I am a creative director working within geospatial graphics for broadcast, the current applications I use costs me $10K per month in licensing... Furthermore I have nearly 10 years in military/broadcast graphics and creative so I do have a lot of experience in this area.
Geospatial software I know of is for PC or Linux, there isn't much out there with regards to Mac version (that I would recommend). If it doesn't need to be geographically correct (just a simple image) the option I would suggest is Inkscape, it's a vector drawing program that *may* allow you to create a map that can be scaled up/down.
If it has to be correct I would try
Geocart it is pricey and has a pretty steep learning curve. The single license is $860 without data, though onto of that the software wont run well on stock hardware, you need a dedicated graphics card with plenty of ram (I would *at least* make sure you are running 12GB)
For instance I am using a custom Linux box with 24GB RAM, 2X8 Core Intels, Quadro 5800FX with 2GB RAM, and yes ingesting a world map @ 500m still runs into the hours.
The cost of mapping software isn't so much from the feature rather the ability to created geographically correct and to scale works, high resolution DEM and satellite imagery doesn't come cheap not to mention you need the computing power for it to run correctly.
My recommendation would be to try to strike a deal with a cartographer, seriously the amount of time money and effort spent on creating your own maps just wont be worth it. Cartographers charge this kind of money for a very good reason
