I have used most of these FRFR's and they can work really well. A solution I have been going with for a while now - which could be slightly more money, but really is the best of both worlds is to have a modular cabinet built. I had one designed by Raezer's Edge. I can mount a power head inside and also use this as a regular guitar cab without the head.
This solution, I have found is a lot more error free from trying to change presets to fit the FRFR you are using.
I used a 600 watt acoustic image head for my 112, and now thinking of creating a 212 with either the same head or a different one.
I suppose you could create the same setup with any head cabinet design you would want.
Again the advantage to me is you get a much better sound, which is less PA speaker-like.
The total cost of this set up was about 1000 US. But again this head has way more options than a class D insert, and a ton of power.
I also have a eq section if I need it, 2 speaker outs a direct out. I can use this head with any cabinet as a regular power amp or with this set up as a combo solution.
So to answer the question does cost matter? - I would say it can depending on what you want for sound.
Can a PA speaker like a QSC K12 or a FRFR speaker work great - it sure can. But with a set up like this, it easy enough to build a modular insert - like a rack and mount what ever head you want in there. What comes to mind is the power stage 700. If you had this cab built with a 19'' rack insert, you could then mount any head that fit the dimension you want - like a Matrix or a PS 700 for example. If you need more speakers, then just add a 4x12 or something bigger.
To me there are some many really great sound solid state power amps out there that can do the flat thing really well that it makes sense to invest a few more dollars and create a speaker you can actually use.
The last thing I will say is this box I have also found creating presets in the studio and then trying them live with this head/combo has been really transparent. I don't have to try to keep adjusting them to the box and focus more on playing.