I'm eager for more information here too. To get max uplink between DN radios I'm seeing they recommend not more than 90meter separation (more if only 1Gbps uplink). Most are going for ~$2000/DN MSRP and $650/CN and we are crossing our fingers to get enough clients connected taken from DOCSIS 3 to make it worth the investment... Need to be able to mesh at full speed and deploy DN's like crazy to make it reliable and fast from what I can tell. If we have to skimp on DN's to try and save money you may as well forget it unless its high density business clients willing to pay high monthly fees.
I'm doing the same math here. What kind of population density do you need to make a $2k AP every block make sense.
I hope mikrotik has a better plan up their sleeve than what these other companies are doing.