Two places I look for anything quilt related: Amazon (so-so luck, but you never know) and quiltshops.com.
I only use Aurifil, and usually a taupe or grey, although I have used a peach color I got on a great sale. It was fine, no showing. Amazon has a 12 pack w. storage box of neutrals for $97.49. A big investment, but works out to $8.12 per spool.
quiltshops.com - entered aurifil sale
http://search.myquiltshops.com/cgi-s...myqssearch.cgi
Also - Walmart.com it's $9/spool.
If you would use a cone: Pumpkinvinecorner.com has cones on sale for $37.99, with large color selection.