If they are the heavyweight ones (??) then about £40 ish.
As ever, depends on how old / condition / have they been laundered etc etc.
I think it is very difficult for someone to give a price without giving some more details.
I would suggest you look through 'completed listings' on ebay - you can then see what is similar in description to your rug & how much it went for.....
Thanks for the advise Loves_orange, Yes it is the heavy weight one blue check with a black cotton lining, good condition although one has small white paint marks, and as yet haven't been laundered, although not that dirty. I also have one medium neck cover to match. I had a look on ebay but they don't seem to be selling, as they have starting bids of that sort of price.
In that condition & with neck cover then prob £35 - 40 as someone will have to pay £10 for it to be washed (I wouldn't put an unwashed rug on my horse). Also postage cost would need to be factored in. I imagine it would cost around £10 to post with neck cover as pretty bulky / heavy.
My nearly new 6' quilted winter stable rug (an Aerborn) only made £7.50 and it was cleaned by my saddler this past summer too.
Now I have a non paying bidder on it and am going to have to relist it this Sunday!!!
Hmph, good luck if you do decide to list it. Hope you don't get the same numpty bidding on yours that bid on mine.