If Thowing Knives were a "grenade" rather than a basic weapon do you think they would see play, or would the still not be worth it?
Making them a sidearm would devalue Stiletto Knives a bit IMO.no sidearm?

They would function better as having the grenade trait sure but the price will have to be ramped up considerably
My gut would be to keep them the same price--I'm still not sure they'd see much more play--but I'm happy to hear what people think they should be priced at.Why not same price?
Considering the nature of what they are Im unsure the "scarce" part of it is much of a limitation in practice. How many shots would a character reasonably expect to even get off during the game at such a range?I will say yes to use them in three situation.
a: to cut cheese
b: at the circus
c: if they were free
But in fairness are they useful weapon or not? I don't see it. Ogryn has a BS that make a Ogryn Ninja impossible (bs5+ scarce)... Escher Wylde Runner has access to the bow wich is far better and for every other ganger at best you have Sx4 range and thus put it the same rage as most pistol.
it's not warger or weapon the issue for me but scarce.
In your case I would say 40 credits. It does have the potential to take down a 6 wound model in one hit after all.I'd want to keep things simple, likely the current profile, drop the short range, add the grenade trait.
How many credits would such a wargear be worth?
Frag Grenade: 30 credits (has blast and knockback)
Krak Grenade: 45 credits (has demolitions. this is it's closest competitor as far as a single target grenade goes IMO)
Choke Gas Grenade: 50 credits (has blast and gas)
IMO it'd have to be much less than a Krak grenade at 45 credits. I think frag serves a different niche.
somewhere in the 10 >= x < 45 range?