Something to consider is that the wireless spectrum is in constant flux these days.
Frequencies that used to be "safe" have been re-assigned for other uses (for example, cellular phones) and are no longer viable. Wireless systems whether traditional UHF or VHF - that were purchased for professional use have simply stopped working.
Also, as production gets more and more affordable - more units are in use - and the possibility of frequency conflicts only increase.
So wireless is getting more difficult to operate, not easier. If you are just looking for something to use for a few years and in limited circumstances where there aren't a lot of other users competing for frequency space, units in your price target will probably be fine.
If you're investing for the long run - it would probably be best to up the budget and look into one of the newer frequency agile digital systems that search for clear frequencies and lock onto them. It's a longer term strategy than fixed frequency these days.