I use the "boxed ones" which I unbox and modify accordingly like removing the LED, push button and connector from the PCB and connected with a short wire instead
You can get the multi modules from Banggood cheaper than that. Overkill, as they will do virtually every mode for every manufacturer - but you can set the 'dial' to the DSM position and they'll then work with Spektrum receivers.
I'm not sure how easy it would be to select DSM2 or DSMX and the 11ms or 22ms versions of those. I normally use the multi module with a Taranis, which communicates with the module serially and selects modes that way - so I don't use the 'dial'.
I'm sure you can configure four different 'dial' positions to give the four possible Spektrum modes, but that would mean a bit of messing around with a PC connected to the multi module - the multi modules don't come set up that way out of the box.
Yes, the Orange DIY modules are now quite expensive and a lot more than they used to be....... However they make for a neat and uncomplicated installation and I don't have the background in electronics that some have to enable me to "adapt" other modules. Having now converted more than twenty trannies I have a system that works for me and I like the ability to fly any model with any Tx so I am committed. Another factor which might make a difference is that the DIY module has an output of 100mW whereas the other DSM2/DSMX options only have an output of 70mW. 'Not sure how much difference that makes practically but it must help!
It doesn't matter what stuff costs really, If you enjoy what your doing and it keeps your mind ticking over, then its worth every penny in my opinion. just saying.....