I'm going to buy 4 foldout chairs, for the garden or for when I need more chairs inside The House. My question is, what should I take into consideration what making the purchase? All I can think of is getting wood instead of metal because of not getting rusty when it rains.
I would get some heavy duty plastic ones this way you don't have to worry about the problem of rust or even termites. I have some heavy duty ones that are very durable and all I have to do is wipe them off and fold them and store. I suggest just check the durability of the chairs and get some plastic ones.
I'd recommend metal ones. We had 3 of them that we used for like 10 years and they never rusted. The frame was made from metal and the part you sat on from cloth. We replaced that cloth once in those 10 years, no other issues. The chairs were used in our garden and for picnic trips. As long as you avoid leaving them in the rain often I think they'll last a life time. So if you want to save some money in the long run, try metal. The plastic kind I don't like that much. They tend to turn darker (dirty looking) from sun and rain.