Price is only an indication not a guarantee. I was told by someone in the textile business that there 12 grades of, I think it's called, dress weight cotton. This is the basic fabric before printing. The same person told me that Free Spirit uses grade 12, the highest so a scrap of FS is a good for comparison shopping.
A number of other factors play into the final cost. You might find 2 fabrics printed on the same cotton base at different prices. Sometimes you can see a difference in the quality of the printing--one fabric has clearer details for example. The wear & handling of both will be the same. Where the fabric is printed will also have a price impact. Japan or the USA or western Europe are going to be more expensive than fabric produced in the 3rd world. A designer name will also cause the price to escalate.
Sometimes I feel ripped off. I LOVE Kaffe Fassett fabrics but the quality of the base fabric is, I feel, inferior to say Free Spirit or In The Beginning, & etc. A real love hate relationship especially with his flimsy shot cottons.
Learn to trust your hand. To save $ shop sales at your LQS. This is a good way to build a stash especially if your stash is nearly non-existent.