There is a huge difference between working full time and getting paid by the hour then building something for so many hours and then collecting money after its finished, I mean once its finished you can walk away and keep getting paid for it 
But as everyone has stated before, IF its good, the price is right people will buy. If its not worth the price then people wont buy thats it. Just like any product in world.
I mean you could of spent 2 years working on your assets and say its worth $40,000 but you know people dont buy your asset because you said you worked 300 hours on it they buy your asset because of the quality of it. I mean someone could build a cube and say they spent 40 hours on it they then whack on $50 for the price, that aint going to sell compared to someone working 40 hours on a great asset. Best of luck to everyone selling their assets on the marketplace.