Probably the cheapest full body motion capture solution out there right now is at naturalpoint.com. The next cheapest solution is the Gypsy, which gets into 5 digit prices. One alternative is rotoscoping; basically filming your actor doing the movements you want, saving the video as an avi file, placing a plane behind your figure in Poser, and using the avi file as an animated texture. You can step through the frames and adjust the figure to match the pose on the plane prop. In either case it would stand you in good stead to download lots of bvh files from the net, and begin to get comfortable with cleanup procedures. No mocap is ever perfect, and there are lots of body parts (like fingers and toes) that you will have to keyframe. Learning how to take to disparate motion files and stitching them together is also a vital skill (and one that will either teach you the ins and outs of your animation system or drive you bonkers. Or both).