Development time price is never selling price, period.
I have worked on some unity / unreal assets that took me 40h just to model them, other guy animates them for next 7h, and next 8h was setting them up in engines, there were 3 to 5 assets in package, so total development price was around 55h * 30usd * 3 = 4950 usd.
And this pack is selling for 30usd. Is compatybile with kubold arms, fparms and alloy physical shader for unity (because standard shader is shit).
Sadly, for content that you made, i dont think anyone would but it, unless its 100% physically and mechanically accurate, so it drops into niche stuff - right now there is no textures, no animations, and i dont even know what market you're aiming for. Turbosquid eats 50% of money you earn at start, after that, taxes n shit.