Remember, those big basement finishing system companies make lots of money (your money) by selling the complete package--materials and labor. In fact, you cannot separate the materials from the labor.
But what it you could get the materials alone and do it yourself? One company that I know of, Wahoo Walls, does this.
Wahoo Walls' pricing is transparent ($149 for a 4'x8' Smooth Tape Edge Perimeter Wall Panel, as of December 2013) and they give you lots of DIY design suggestions.
Downside with any big remodeling materials ordered online: freight costs. Unfortunately, online estimation of freight costs isn't yet available at Wahoo Walls, but owner Anne Wheatley Parker tells us that plans to eventually put this in place.