Body kits are a matter of preference when it comes to the style, but unless you want to spend a bunch of time reinforcing and modifying it to make it fit properly, don't buy a cheap one.
When speaking to someone about buying one, don't listen to the bs. If they want to fit it while its fresh, to 'make it fit better, while its still pliable' its a kit that doesn't fit properly.
Cheap kits also contain less fibreglass. Hit a grasshopper on the way home and watch them shatter!
I bought a cheap VX-R8 kit for my VS. I hit a couple things on the 3000k journey home, which did far more damage than they should because the kit was badly made. There was actually dry fibreglass mat under the gelcoat! Saving money on resin... The fit was also bloody terrible.
However... its not hard to remove a kit and beef it up with a bunch more fibreglass. Its not hard to reshape edges to make the fit better. Just so long as you want to do the work.
A decent kit, which bolts on fitting right and doesn't shatter with an angry look, costs thousands, and there are less options available to you. A cheap kit (mine was $650 without the bonnet) will cost you to reinforce and correct the fit. Its up to you which way you want to go. (note that on mine, the bonnet is very well made, strong and fits perfectly.. and also cost me $650 from a different company.. just the bonnet. You pay for quality.)
Spend even more for original stuff and you should get plastic instead of glass, and this is much, much better. You will pay thru the nose for it though and your choices are going to be limited.
In the end, I love the look of my VS, and its all worth it