I would say not man. I think saving up for a nice new bass is almost always a better idea than trying to upgrade a cheap or crappy one.
I had a thought; My older brother had a crappy starter bass that he defretted, but gutted the electronics. So if I put that neck on my bass.... I'd essentially have a functional fretless bass for the price of however we decide to finish the neck!
Hopefully the neck fits.
And I'll still get a nicer one later on, obviously.