Did your guy check the static pressure before and after, or just swap the cabinet in? Because $90 a month in January in Red Deer is actually huge, that's not nothing, and most people I know who skipped the HRV did it for the same reason, the upfront cost stings. The thing is those two fixes do different jobs, the filter cabinet stops dust from getting past the slot and eases the load on the blower, while an HRV deals with fresh air and winter moisture. So you didn't really pick the cheap version of the same thing, you just fixed a different problem first.

Switched my little bench mill over to a probe about four years ago and it was the best money I ever spent on that machine. I still keep a feeler gauge and a sheet of paper in the drawer for when a probe dies or I'm doing something weird with a tiny drill bit. What sold me was running the same job over and over and getting the exact same numbers every single time instead of being off a thou depending on how tired I was that day. The trick is you still have to keep your holders and collets clean or the probe just gives you the same wrong number faster. Learning to set the probe and trust it took me maybe a week, the first few days I was double checking everything by hand anyway. Now I touch off with the probe and then spot check one tool by feel just to keep myself honest, and 99 times out of 100 they agree. The feeler gauge is not cheating, it's just slower, and on a Haas the probe pays for itself the first time you scrap a part because you fat fingered a shim.