I run a Labradar. But, I shoot, a LOT. About 35-40 different rifles a year and 2800-3000+ rounds. And do a lot of tinkering. For a need of once or twice a year, I would just find someone else who has one and go shoot with them when you need it. Twice a year is not worth a $550 investment.
But, they are very accurate. They also calculate ES, SD, and average speeds. And you don't have to strap it to your rifle, can shoot multiple rifles or pistols or bows in a row without messing with it or moving it from one to another.
I just finished load development for my new 6CM pushing a 105 Hybrid @ 3063fps for my target loads. I had shot it at 404 for the ladder test, then only at 100 & 200 for the load workup.
Last week, with the info I gathered, I went to stretch it's legs. Went out and started right at 545, made a 1st round hit within 1" of POA. Then, 765, 851, 921, 1181, 1251, all 1st round hits on small targets. Without an accurate speed input, no way the longer shots would have been on target.
Before you discount your current chrono, make sure your inputs are all correct for your gun and bullet info. Just had a buddy who messed up a couple inputs, and his drops were off. He tried to true his velocity which changed by about 100fps too, and it threw everything out of whack. Once we got the info corrected in his ballistic program, he was within .25MOA from 400 out to 900+. Trued his velocity off 5 new verified drops, and it only changed his speeds by about 20fps. Close to what his chrono had originally showed.