Perhaps you’d do better using something even cheaper than LoRa then, for example you could use nRF24 radios, the descendant technology that is BLE, or the ESP8266 “direct” mode that uses the wifi radio in a non-wifi way. I’ve been toying with the idea of implementing something “inspired” by LoRaWAN (but not LoRaWAN) on top of a different sort of radio.
Of course, there are also plenty of legitimate uses of the LoRa radios, that are not TTN and are not even LoRaWAN but more peer-to-peer architectures. Amazon’s offering seems to be built on the idea of an infrastructure based on a high density of node-class radios in people’s porch surveillance cameras.
Most of the issues with, shall we say, “single channel abominations” only come about if you feed data into TTN. If you keep everything in your own non-TTN ecosystem (ie, install a personal instance of LoRaServer, or write something custom, or at least only forward to TTN traffic that matches your node ID) and don’t use the band discourteously they might have their place. But such a project would be a lot of work.
It happens, that the “problem” of “single channel abominations” (and a few other problems besides) could be readily solved if the TTN backend folks would simply recognize an optional field in a signal report to the effect of “acceptsDownlink”: false and if they see that, not try to route any corresponding downlink through the, er, “abomination” sending in such a report, or even go a step further and ignore its report for ADR purposes, too. I understand the urge to lecture people who want to build single channel setups, but there are quite simple things that could be done server-side to make the issue a non-issue for others.
FWIW, while it is in theory a “real gateway” I’d strongly discourage anyone from buying a TTIG until either the issue with it are solved, or source code is released to a allow the community in general to work on solving them. Many of the other options with true 8-channel concentrator cards seem reasonable - given an active business need I’ve bought a lot of equipment from RAK and a little from nFuse, and the impression is that the multi-channel offerings from others would be comparable.