“If you have never run a cart what the hell good does it do to see it?” 
I don’t think you need to have dogger experience to see quality and craftsmanship. Look at the complete mess on another thread. Secondly – the more exposure you get to different carts, the better the idea you’ll have when time to purchase. 

outstanding point Joedog.  if you’re really, really new, get a used cart from Craigslist.  It’s local so you can go see if it has tires and a sink.  If you know exactly what you want and want to invest more, go for it.  however, all you really need is the basic licensing requirements, a dog, a bun and some mustard to start hot dogging.