depedning on the model between $190 and $400 currently
the sporter MSRP's at $189 - but is limited to barrels (or suppressors) 1" in diameter or less and doesnt have all the same functionality as the V3
the V3 is their full feature model, but MSRP's at $400
here's their application chart
3rd party retailer prices are a bit lower, but not by a whole ton. i think i recall seeing sale prices down around $360 or so, but please dont hold me to that number.
however - ease of setup, and the fact that it can be used at ranges that dont allow traditional chrono's to be setup really make this thing shine. The other thing is lighting levels dont effect the magnetospeed in any way, shape or form so its quite a bit more versatile int hat respect.
the one place where the magnetospeed does have a weak point is with handguns. There is a rail adapter that fits most semi-auto guns with a mounting point (for like a light) but it doesnt fit them all (my first gen XD is a perfect example) as some of the rail mounts are proprietary .
also you obviously cant use it for archery testing either.
however when you weigh those small cons against all the checks in the 'pros' column, it definitely comes out miles ahead.
the only thing that's currently surpassing it in versatility and utility is the Labradar units, but those are quite a bit more expensive
hth