Would Vue and Poser be good for modeling/art? A friend of mine said some concept art is done in poser. How good is its exporting capabilities? Price really isn't an issue

Poser(not sure about Vue) has very little modelling capabilities... it is used mainly for the dress up and posing of pre-created assets. Its good at what it does, but is no substitute for a modelling/animation program.
That said, yes, some artists use Poser for concepts... not so much as rendered concepts (because the assets already have to be done to be used in Poser), but as assembling characters into poses with makeshift props, to figure out lighting, etc. This is then all painted over, usually. The reason people use Poser, and not, say, Maya, is because of the aforementioned pre-built libraries included and available for purchase, and the ease of mixing and matching styles and clothes and props.

From what I've seen, Vue is mainly for creating images of outdoor scenery. In terms of "modeling" I don't know how practical it is overall, nor what formats it can export to.

As for Poser, Professor 420 is right. There's no real modeling in poser... just modifying and manipulating stock content really. You can however, import and export many formats, but you can't package direct variations of Poser's 3d models in products you plan to sell. However, to create concept scenes and artwork, with creativity and patience, I think Poser can be great.
I.e.: http://demonsword.deviantart.com/store/

Plus, one thing I'd like to note: A really cool thing about Poser is it can export the BVH (mocap) format and all it's humanoid models come rigged and ready to be animated... which IMHO makes it super-handy for developing quick animations for indie 3D games.

or you could use it to make normal map so that your lowpoly looks real high poly
in a 3d modelor like 3ds max