many moons ago, i wanted the "best" hygrometer. Me and Arlin Liss found a recalibratable hygrometer with a professional salt test kit. It was well over $100, but it worked perfectly. I had a few doubters regarding the accuracy, so a fellow cigar electronics manufacturer volunteered to get it tested at the high dollar lab that he used.
The results were perfect. The real killer was replacing the salt test kit. If I remember right, it was about $70 to replace the salts when they dried out.
we are now lucky enough to have the recalibratable hygrometer with the slat test kit from Humidipak. Just as accurate as my high dollar kit, and replacement claibration kit is about $5. How can you go wrong? When you can but the best for $25, does it really pay to try to get something for less $?