You can make your own if you want to for under $20. The most expensive parts are the wood for the makeshift tripod.
Get two cheap red laser pointers for the lasers. Have each fire into a phototransistor to control the current in a stopwatch, which I took out of the case and mounted into a hobby box. The phototransistors run into the same stopwatch with current directed via diodes so the two timing gates don’t erroneously stop the watch randomly.
When the first laser is broken, resistance drops in the photodiode allowing current to flow and starts the stopwatch. When the second laser is broken it does the same, which stops the stop watch. Two microswitches (think arcade machine) are also wired to the stop watch to allow you to reset it.
I still need to test the accuracy of the gates compared to an expensive one. I never mounted mine from last summer when I made them, but they definitely work.
I think I made that sound more complicated than it actually was, if you want more info on it or anything send me a PM, or I can write up a wiring schematic and post it.
Would you be so kind to post a wiring schematic please? It would be of great help for me.