As a prospective buyer - if I don't like the price, I walk away.
I might do a "would you consider $ for some item?" and see what happens - especially if it's something I'm only somewhat interested in. I consider "negotiating" part of the shopping experience - as either a buyer or seller. If the seller doesn't like the offer - he/she can say no, give a counter-offer, or agree to my offer.
It's your stuff - if you want to charge $100 a yard for something, you can.
Like my Mom used to say - Fabric doesn't eat much (except space) - and usually doesn't have to be taken outside for potty breaks.