Telecom grade MW P2P links start at 20K and upwards. They do also however work on licensed spectrums. The new un licenses 24 50 and 60 ghz links can be really cheap, but I don't know how well do they compare to the bigger telecom ones. RF equipment is pretty darn expensive to make, the telecom one have pretty impressive "RF dark magic" eco chambers milled out of aluminum blocks and many other cool features. The new commercial ones seem to be pretty simple and mostly solid state not much more complex looking than your typical wifi router. How do they fair with weather and interference how well do they coexist with each other, and how reliable are they in the long run is another question. Some of those MW drums can operate for decades I'm not sure about the 300$ or even the 3000$ ones.

yeah, no. Not in 5 GHz. Sorry to tell you the marketing hype doesn't jive with reality. Two Mimosa B5C radios and two 32dBi dual polarity high performance dishes will make a nice link, and it is awesome to be able to buy a radio link that will do dual polarity 256QAM modulation in 20, 40, 80 MHz wide channels, but it will not be 750 Mbps full duplex.

In the real world more like 250-300 Mbps full duplex, or slightly faster than that if you tell it to allocate greater bandwidth in one direction in a ratio like 75:25.

You can't compare a Mimosa B5-Lite or B5C to a carrier grade ISP, FCC Part 101 licensed band radio (6, 11, 18, 23 GHz etc) that's fed from dual -48VDC A and B power feeds and has multiple SFP slots in it.