There are many different opinions on this.
Mine comes from overseeing the AVL needs of a large organization with relatively limited resources.
As much as I want to be able to deploy 500$/channel wireless, it’s a bad use of money and I will no longer do it. This opinion is based on a lot of expierience and more importantly, a lot of disappointment.
My recommendation, in the current RF climate, is to only buy professional quality, digital transmission gear operating in the high 400 to low 500 MHz frequency range. I would also argue it should be narrow-band capable. This is going to put you into the 1300$~1600$/channel range with a head mic depending on if the gear is standard or narrow-band capable.
If these numbers don’t work for you then you should either work within the confines of wired mic options, or rent the gear in for the show.
As painful as it feels to see the money “disappear”, renting the right gear is often the better answer than buying the wrong gear.
Again, i would love to have a reasonably reliable and reasonably durable 500$ belt pack option out there. We would use them all over the place. But that product doesn’t really exsist, and those products which do exsist in this price range are increasingly being ran over by the ongoing FCC restacks and an otherwise ever-less-friendly RF environment.