I won't spend too much time on the Thermaltake Core P5 TG V2 price tag as the case is not meant to be the most sensible choice in general. That said, at $190 dollars, it is quite alright, especially considering the inclusion of a PCIe ribbon cable. Sure, unlike traditional enclosures, you won't get any fans in return, but the MSRP is still interesting enough to sway people into giving the open air chassis format a real shot.
Also, I don't think even for the price tag, the Core P5 can be considered a sensible choice when considering that you can get a feature-packed tower chassis with all kinds of cool extras for that price. But, sensibility doesn't really play the biggest factor here. One could compare the Core P5 TG to a convertible. Yes, the classic solid top variant is cheaper, more sensible, probably last's longer, and offers real trunk space. For those going for a convertible that loss of space, the potential holes, and downsides of a canopy are far outweighed by the feeling of the breeze in one's hair in the few months of the year that permit it. The Thermaltake Core P5 TG is just like that: sure, you don't get the pre-installed fans or ability to install 2–3 different radiators, etc, but you do get the features that count and allow you to build a fully capable, potent system with the ability to let your room's breeze blow across while showing it all off. Add the fact that the Core P5 is wall-mountable and you have plenty of reasons to go for it.
With all that in mind, the Thermaltake Core P5 TG V2 is both fun and more than sufficiently functional, with its high quality build to round it all up.