Here's how the fabric industry works in a nutshell...

If you buy from a maker loose yardage from a company such as B-Y, for example. They are going to mark it up from their bolt price and sell it to the dealer who is also going to mark it up to sell it to you. Typically a fabric they may buy on a 50-yard bolt for $ 25 a yard is going to sell to you as the customer of the dealer for about $ 70 a yard. They are not in the cut yardage business, they are in the furniture making business, so they really have no interest in deep discounts on cut yardage.

Places like you have come across on the web that sell for $ 20 a yard are brokering closeouts and seconds. There are a ton of those out there in the industry. Fabrics don't sell well, or go out of style, they go to the discount clearance guys for pennies on the dollar. Also, all seconds go there, too. Fact of the matter is you can't begin to buy a first-quality, well made Chenille for that price as a retail consumer. But that doesn't mean you have to steer clear of it, either. Request a sample from the seller and see what it looks like. If you decide to buy it, have it come to you first, then unroll the bolt and inspect it for flaws. Any flaws you see, mark with a "X" with masking tape and roll it back up. Its up to you to mark the flaws, the factories working on new pieces assume its all first quality and if you don't, you make see that flam in the middle of your seat cushion.

For a small project like a rocker, you might only need a couple yards - just go to a local fabric store in your area and pick it out - that's my suggestion.