Can I ask some follow up questions to help understand your dilemma better? And then I'll add my two cents based on what I'm guessing your answers are :)

You want to reupholster the chairs in order to sell them, is that correct?

Is this a diy?

For the amount of time and money you will spend, you will NOT recoup the resources you put into reupholstering these yourself. Particularly since you're asking where to buy upholstery fabric, and $40/yd seems like a lot to you, it sounds like you have zero experience with this. Which means your efforts will look amateurish, which means you will get a lot less than what you put in.

A better course of action is to steam clean the chairs, give the wood a good wipe-down, and sell as-is to someone who will create the look they want with them. You'll still get more money than from a diy, you'll have an excited customer, and you'll have more money to invest in a good quality replacement.

If any of my presumptions are wrong, please do correct them :)

@apple_pie_order, great minds... :)

Do you have a Hobby Lobby Store near you? They have lots of great fabrics to reupholster your chairs.

You need three quarters of a yard for TWO chair seats, and a staple gun. No welt. For 150.00 all in, you're renewed. There are a hundred online fabric sources, you can even get samples.

@Jan and others, do you think the time and money invested will be worth it, considering s/he will be selling?

I just feel it limits your market to people who share your taste, or people who will reupholster to their style anyway. I'd rather buy a clean chair with a blank slate and a couple of stains than a brown or red with brand new fabric that I would have to replace to match my own dining room.

OP as an investment for sale, at least use a neutral grey or beige that is likely to appeal to the largest market. Decidedly no red.

Nobody buys anything that looks dirty....... : ( then THEY have to ask the same question. So...clean and NEUTRAL upholstery unless you're keeping them. It's not brain surgery, it's 150.00 and maybe more $$$ RECOUPED. OR KEEP THEM!

Thank you all for your feedback. All good points. I will reconsider the color and look into steam cleaning.

BTW is there an upholstery material that is more resistant to stains than others? I was thinking of getting a handyman to upholster it.

I do feel I will have to let go of this set because it is huge. We have not used it much. I need to get a casual dining set because we don't have a breakfast area and our lifestyle has changed since we bought it.

For 20.00 bucks a yard, you can have performance velvet. Three yards will get you six fresh chairs! Take the darn seats off, number them, with a match to the chair. Take them to an upholsterer. Or have the "handyman" do them with a staple gun.. and screw them back on. By the time they come out to steam clean, you could be DONE. In Buckwheat

http://www.potterybarn.com/products/1896018/?catalogId=83&sku=1896018&bnrid=3380801&cm_ven=Google_PLA&cm_cat=Shopping&cm_pla=Feed&cm_ite=Google%20Base-1896018&kwid=productads-adid^154026493806-device^c-plaid^64621366589-sku^1896018-adType^PLA&gclid=CJzhzajNlNICFQ1MDQodfAgPPA

As others have said, it is VERY easy to replace fabric on chair seats as long as you don't have to do the welt. You would be shocked at what you can do with a screwdriver, scissors, and a staple gun! Especially if you choose a fabric without a pattern.

There's a fabric on the market called Crypton, great to use for heavily used furniture. Pet and kid friendly, easy care and clean up.

As some of you have suggested welting is hard to do, can I remove the original upholstery and get rid of welt with it? Then I can reupholster the chairs.

You can remove the welt, but you may notice a little bit of a gap between the bottom of the chair seat and the chair frame. You can compensate by adding a layer of batting over the chair seat before you upholster them.