The best quality dining chairs can cost a lot as you tend to pay for craftsmanship, premium materials and manufacturing processes.
Single chairs of this quality may push above the £/$250 mark, but they could last you a lifetime and generally speaking, the higher the price, the more durable and long-lasting. That's not to say you can't find more affordable options of great value that will last a number of years.
UK retailers like Dunelm, M&S and Next now offer dining chairs for around £200 for a pack of two, with Habitat having sets for even under £100.
Then if you shop stores like Wayfair, West Elm and Overstock  or The Home Depot you can find sets of two starting from around $250. For a little less you could even consider buying unfinished dining room chairs The Home Depot and then painting them in a color of your choice for a bespoke finish!