Lowes [lowes.com] has 11.7" square patio stones [lowes.com]
for $.88 in various colors depending on location. Home Depot has them for $1.28 so you can price match and get them for $.79 at HD.
These are good for a simple walkway or small patio area but not for autos.
Also available in grey or tan at most stores.
As with all Lowes deals, prices may vary by location.
Prices good through today only - March 14, 2018. DEAL NOW DEAD.