Can you possibly recommend a gas grill that will last more than 2 to 3 years? I've bought everything from $200-$500 and they just don't last. The burners always rust out.
With proper care and maintenance even a cheap grill can last a long time. It has to do with keeping it clean and out of the elements when not in use (covered) that will help ensure years of enjoyment.
I do know that even with care things can and will rust with outdoor appliances and there are many sites devoted to burner repair and replacement that can be more cost effective than replacing a grill year after year. Here is an example of a site that explains how to repair gas grills : http://bbq.about.com/cs/replacementparts/a/aa071100a.htm
If you do decide its more work than you want to do and plan to replace it look for a grill with options you will be using over a grill with lots of options you will never use. Invest in a good cover and use it when you are not using the grill. If it snows in your area maybe move the grill to the garage for the winter than allow it to sit in the snow. Do light cleaning often and do an annual major clean in the spring which includes checking all components to make sure it operates safely.
I would just say look the grills over at the stores you go to. Be wary of stainless as most are not 100% stainless and the best way to check would be to bring a magnet with you. For me personally when it comes to gas grills I like some of the sears grills, I also like Webber and the big green egg which is my all time favorite.
I hope this helps you if not feel free to ask a follow up question.