Been doing some iBeacon dev and deployments for about 8 months. The estimote hardware is just outrageously expensive compared to what you can source from China with little effort. As in, 3-4x the cost. If you're just doing simple BTLE proximity I don't know why you'd need a $30 beacon (I guess they have some other sensors built into their beacon as well?)...if you're making a toy, fine, but if your intent is to deploy thousands (or even dozens, really) of beacons it just doesn't make any sense. I suspect in a year's time generic hardware will be had at < 1/10th the price of an estimote.