It's going to be a tough sell, as the Nikkor 50mm f1.8 S is an amazing lens for a reasonable price
I don't think it's that hard to sell a lens with such optic quality for USD $199 vs the $625 Nikon 50 F1.8.
I think the biggest challenge for Viltrox ( and any other 3rd party lens manufactures) is how to get their name out there, I bet other than those people hang out in the forum, or follow these gear release really closely, most people won't even know what the hell is VIltrox, Sirui, Yonguo, 7Artissans, TTartisan, Meike.... it's just to many of those and it can get pretty confusing. i still run into people feel "shock" to see I mount a no name " junk" in front of a $5000 Z9, just few weeks ago I was shooting with the new Tilt Shift Laowa on my GFX100s, few photographers noticed the GFX and started a conversation, but none of thwm know what the hack is this Laowa thing is .....
With that said, any new 3rd party manufacture will face some tough time and have to sell things at much much lower price to get people's attention, look how long it took Sigma to get their image up, for the longest time, Sigma is just some crap for those can't afford a good OEM lens,