Not much less than the HDHomeRun and would need to be a bit tech savvy to get it to work, BUT, I have considered picking up the "Winegard SensarPro Signal Strength Meter".
It shows signal strength for any one channel, or scans for others with an optional amp...
The problem is that it is meant to go in RVs, so it is powered by direct wire 12V DC... Meaning it cant be used out of the box as is, would have to wire in a AC -> DC converter or a battery pack.
I planned to pick up a hobby box of some type to create a portable meter / tool.
Of course, once you buy the device, plus the accessories to make it work outside an RV, its almost as expensive as the HDHome Run, but still a lot more portable.
$71 new but Amazon has them as a warehouse deal for $56 (I have seen them as low as $45)...