As commented by others, saving few dollars after getting a >$4k camera is not going to make the difference.
Anyway, as per what I've found around, the Leica protective case is indeed the cheapest offer around. IMHO, though, it's simply ugly and, thinking again to the concept of "dressing" properly such an expensive jewel camera, I'd say the Q deserves something really pretty.
A factor that has to be considered is that, differently from the M, I consider the design/finish of the Q not iconically retro, but neoclassic. A very vintage looking case, accordingly, doesn't do the job IMHO. Anyway, the cases that are on the market from Angelo Pelle and Luigi's Leicatime (which are probably some of the brands that are more traditionally linked to Leica) maybe look too vintage. Also, I don't get this thing of the metal grip on the Angelo case...
Arte di Mano (which is Korean and not Italian) makes 2 different cases, one with minimal added grip and one with a more consistent one. The former is what I consider the nicest Q case around yet, but it is truly expensive. For the M, Arte di Mano makes also a case that covers the camera plus the multifunctional grip: a Q version might see the light.
Gariz has not announced a case for the Q yet, but it will jump for sure on the bandwagon. Gariz cases tend to be way cheaper than the offers from Luigi, Angelo and Arte di Mano; also, they are intrinsically modern (but they cover less...) and they could make a nice fit for the Q. Personally, I find the Black Label series one for the M very good looking, and I expect Gariz to release a similarly designed one for the Q.
So, if you're concerned or cannot make your mind yet, just wait if Gariz released one (I guess you could email them to inquire): it might be the most affordable but still good looking one.