They cost 100$ from Brownells dude? If you cant swing that, use a friends, but in all honesty you don't need one. There are only two ways to get your dope and they both rely on the same method for 100% certainty.
With the advent of modern ballistics software a lot of people seam to be under the impression that conformation of actual drops is no longer relevant. However that's a misnomer to say the least. Your going to have to go out and shoot your dope from zero to what ever distance you intend to shoot, then add the data to your ballistics calculator and adjust your muzzle velocity until your actual dope and the dope the calculator is giving you match. In a round about way this will give you what you asked for in your initial question.
If you do acquire a muzzle velocity make sure you still shoot the drops to confirm and adjust the calculator to reflect your actual drops.