For whatever it's worth, I agree with your logic. For the absolute budget people, 9x with stock module. FlySky is okay... fine for park flying for sure. If you are considering a 9x with FrSky module, I don't think there is any price difference really to get a 9xr. $60 for the 9x with FlySky module (that you're not going to use), or $60 for 9xr without. Likewise, there is a relatively small leap between a 9x plus an ISP programmer to flash OpenTX and a 9xr with FrSky Module. Maybe $15 difference. So if you want OpenTX, just get a 9xr with it already installed, unless you already have an ISP programmer at home for some reason, in which case you could go 9x with stock module and OpenTX.
As I see it, the main thing Taranis gets you is much better quality hardware (switches, sliders, gimbals), telemetry with no fuss (awesome, but is it worth an extra $100?) and the ability to have both a module and the internal FrSky, for mix-and-match with different types of models (e.g. UHF or BnF DSM). I think the decision between a stock 9x and a 9xr is pretty tough. Somebody who can come up with $60 for the 9x... could they save a little more and get a 9xr? I think the 9xr offers much more value for money with the OpenTX firmware and the FrSky module. The Taranis is less of a clear choice, at something like double the cost. It's better, no doubt, but a lot of people are going to have other things to spend that money on.
