Buying a garden dining set should not be taken lightly. You will spend a lot of time using it and it will also say something about you and your garden - so choose carefully, taking into account your garden style, your lifestyle and the statement you want to make to friends, family and neighbors!
Plastic dining sets are cheap (relatively), low-maintenance and tough but will lose their looks over time.
Wood dining sets are warm, stylish, more expensive and need some maintenance - but $ for $, timber is likely to give you the most pleasure over its lifetime.
Metal dining sets vary from cheap to very expensive. Aluminum is probably the pick of the crop - light, durable, strong and attractive. Cast-iron is heavy, very durable, classic and stylish. Steel can be sleek, stylish, modern and - if well finished - durable.
Check what is available, think about how you will use it and what suits your taste - and buy something that you know you will use and whose maintenance demands you can live with!