I get this question a lot. Best answer I can offer is divide the cookers into two groups: ceramic kamados and steel kamados. I don't think it's fair to compare ceramic and steel kamados together as each has a different set of maintenance demands.
Then for each group, compare initial cost, warranty and dealer support, as most of these cookers are going to need some type of repair over their life time. If it's cheap going in, chances are it going to require more warranty or repairs during ownership. If the dealer, distributor or home office is not local, then you need to consider the hassle and added cost to ship or freight repair parts. It's expensive to ship or freight ceramics.
Chances are parts exposed to weather are going to have the shortest warranty, thus the added burden to maintain. So, a cheap kamado that includes a cart may not be so cheap five years from now when the welds on the cart have rusted through.
Also, with ceramic kamados, if you not comfortable with the quality of the ceramics, don't let it slide. Good chance, you'll be replacing ceramic parts. The ceramics may be covered under warranty but the cost to ship replacement parts may surprise you.
All the kamado style cookers need some type of honey-do repairs during ownership. Before a purchase, one should weigh initial cost to buy, additional cost during ownership to maintain, how handy you are to do repairs and how available replacement parts are. Once you get these answers, it not hard to find a viable kamado by surfing the forums, especially this forum.
Thanks to all for your support of ceramic grill store, it's greatly appreciated.