for cars you'd be better off with pet-g than abs. Much easier to print with and higher glass point.

How long does 1 kg last ?
That depends entirely on how you slice it. A large model with say 3 layers and shells and 10% infill might only weigh a 100gms.
The same thing with higher infill and moere shells could weigh 200, 300 etc.
As long as you're sensible with your slicer settings a kg can go a very long way indeed. And with reasonable shell thickness and low infill. Items are still surprisingly strong.

I'd have gone for tjhe monoprice (wanhao duplicator i3)
Having just started my first kit build - I'm bloody glad it's not my first printer. :-)

I would always recommend you buy a ready built and tested machine for the first printer.