It is super pricey indeed.
I'd suggest the Phatlab Chimera as it is a hybrid tube portable amp and its predecessor, the Sassy II, was comparable to the C9.
Also the Romi BX2+ is a fraction of the price and has more driving power and works great for folks who've tried that pairing.
Haven't tried the iFi stuff so can't speak to it.
The DX300 is still pocketable unlike the M17 or DX300 Max, and I'd go for the latter options over a stack if you want to keep portability higher.
That being said, the VC is a large headphone and I cannot imagine leaving home with it on my head or lugging it around to and fro, so VC in and of itself to me is highly unportable and I'd be terrified to take it out into public as I treat it like a crown jewel, but as usual, that's just me and to each his own, just go with whatever setup you prefer
My use case was searching for transportability within my house, take it from room to room, etc.