I suppose if you want to buy them from a brick and mortar shop expect to pay more. The average price online was about $210 per sub. Either way you should be able to have a great box and sub for around $650 or less.
For the price of those subs, I'd go with Audioque, Digital Designs' sister company.
1969 Chevy RCLB C10 350/TH400 SOLD
2007 Chevy RCSB 4.8 4x4 LS SOLD
2008 Chevy RCSB 5.3 4x4 LT SOLD
2010 Chevy CCSB 6.2 4x4 LT SOLD
2005 GMC CCLB DRW 6.6 Duramax 4x4 191,000 and counting
2013 FORD CCSB F350 6.7 Powerstroke 4x4