my local quilt shop has a whole shelving area---6 shelves of white on whites and another whole (book case sized) section of creams/whites/ black & whites---if your local shop is not carrying many maybe you should talk to them about it---sometimes they forget people need neutrals/blenders/backgrounds too-
if you join the fabshophop you will have access to something like 170 shops across the country to browse- there is a wide variation in pricing/specialties/fabric lines/ you can find most anything you want-at prices that you like....i just needed a 1 1/2 yd white on white- and had something like 37 different ones to choose between---for $7.50 a yard- beautiful fabrics! i love my lqs---i always start there- when they don't have it i then go to the shophop participating shops and start looking