got a bnib Qstarz lap timer, retails $399
My price shipped: $325
You can load maps to the lap timer or program the start/finish lap. It will also give you predictive lap time on the fly, if you are going slower or faster it will glow green or red and show you how much faster/slower you are going. Will output datalog in the Qracing software as well. You can compare different lap times up to 3 laps at once, and play the data live.
Can be used for circuit racing, drag racing, 0-60 times, or any determined speeds.
full details on the lap timer:
LT-Q6000