Is this a good deal? I have never purchased from them.

saveoncrafts
http://www.save-on-crafts.com/whmubo10co45.html

They have unbleached and bleached muslin on sale.

100% Cotton White Bleached Muslin 45 inches wide x 50 yards for just $79

Regular price $199.50($3.99 yd)

White Bleached Muslin 45" x 50 Yards 100% cotton. 180 count. Permanent press finished and pre-shrunk. Machine wash, warm, delicate cycle. Tumble dry, low. Use cool iron.

From Springs Industries.

Sounds good to me.