Thank you Kryo.
If you are not familiar with the game engine and you don't know what role things like heightmaps, strata, decals, procedual skydomes, props, bps, markers, path nodes, emitters, albedos, bump and normal maps play in the SupCom engine, please don't even try to guestimate a price tag for a Demigod map. I'm intimately familiar with SupCom maps and the game engine, I have seen the beta 1 maps in the editor and I would not even dream to guess how long it takes to create maps like this.
The real question here is: Can a modding team do it? Yes, they can! But it will take them weeks and hundreds of hours of hard work to present anything comparable if they start from scratch. To create a completely new amp you will need one better two 3D artists, 2 texturers, a scripter, someone familiar with the map editor and someone with experience for effects.
If you settle for a map based on an existing map and reuse the background and a bunch of textures, it will be a lot easier. This could be done in a realistic timeframe with 3 or 4 dedicated modders.
Moving towers and forts around, changing creep paths, textures and the like can be done in Notepad++ and Photoshop on a weekend - if you know what you are doing.
I have not looked very deeply into Demigod maps yet because I dont want to waste my time if we dont get a map editor and importers/exporters for 3DS and Blender. But I think my assumtions here are pretty accurate from what I've seen in the beta.