Swallowtail, it is interesting. And I wouldn't think there is any "price fixing" or similar or anything shady about that. But people (tuners, techs) talk, even more so today when we can chat with people around the globe nearly instantly on multiple media possibilities. If 30 people that are out there tuning across multiple cities and states and mostly being pretty close to $175/tuning, it's not a surprise for someone starting out to think that a decent tuning should be worth around $175.
The natural order of human beings is that some will think that they can charge less and be happy with that. Others might think that they will charge more than that. Either may have legitimate reasons and they may have different attitudes towards what they're doing. For instance, one might say, "I can do an OK tuning and be in and out in 45 minutes, I'll make it $125 for a tuning." Another might say, "I want to plan on a 'service appointment' where I will not only tune, but plan on spending an extra hour or so with things like cleaning, voicing, regulation, just going a bit above and beyond, and I'll charge $500 for a 3 hour time slot." (I made those numbers up, BTW.) Neither are necessarily wrong. Different customers may gravitate towards one or the other for those or other reasons, or towards others who do similar work that are in between in both price and expectation. If they happen to end up with a decent tuner who does a good tuning and it happens to be around $175, I wouldn't be at all surprised. 🙂