Hi Seth,
Following are a few more considerations when looking at ROI's and work efficiencies of low cost, less accurate receivers vs full gnss (multi-constellation) bluetooth enabled receivers that work with Collector and just about any device.
Take a look at Eos Arrow GNSS receivers; especially the Arrow 100 or maybe the Lite. While it costs more than a Bad Elf and other low end receivers the total cost of ownership can be higher for cheap receivers.
For example, if you want sub-meter accuracy, the BadElf can't deliver that in most cases, and if you can accept 1.25m from the Bad Elf by waiting 4 minutes, how much productivity is lost compared to 15 sec occupation time (or less) using a more accurate receiver like the Arrow 100? The cost of labor due to slower performance from the cheap receiver quickly becomes more expensive than the higher capital cost of a better performing receiver.
And, Arrows leverage investments already made in front end hardware, i.e. tablets/smartphones and software/apps, not to mention working seamlessly with Collector.