On sale now on Amazon. $11.91, which means you would have to buy three for free shipping.
http://www.amazon.com/gp/r.html?R=3E4QRGRIITSRS&C=K0XTUO4Q4AY7&H=EAVH3JYCCIK481CZGOOYYIM8AQOA&T=C&U=http%3A%2F%2Fwww.amazon.com%2Fdp%2F0195098315%2Fref%3Dpe_147100_25779860_pe_vfe_dt1 (http://www.amazon.com/gp/r.html?R=3E4QRGRIITSRS&C=K0XTUO4Q4AY7&H=EAVH3JYCCIK481CZGOOYYIM8AQOA&T=C&U=http%3A%2F%2Fwww.amazon.com%2Fdp%2F0195098315%2Fref%3Dpe_147100_25779860_pe_vfe_dt1)
Other books in the email
Washingtons Crossing $13.57
http://www.amazon.com/gp/r.html?R=3E4QRGRIITSRS&C=K0XTUO4Q4AY7&H=HWMFAWDTDFZHNUTZPSMDAHEUATCA&T=C&U=http%3A%2F%2Fwww.amazon.com%2Fdp%2F019518159X%2Fref%3Dpe_147100_25779860_pe_vfe_dt2 (http://www.amazon.com/gp/r.html?R=3E4QRGRIITSRS&C=K0XTUO4Q4AY7&H=HWMFAWDTDFZHNUTZPSMDAHEUATCA&T=C&U=http%3A%2F%2Fwww.amazon.com%2Fdp%2F019518159X%2Fref%3Dpe_147100_25779860_pe_vfe_dt2)
The Glorious Cause $16.36
http://www.amazon.com/gp/r.html?R=3E4QRGRIITSRS&C=K0XTUO4Q4AY7&H=PRTHMZ2AJCA1DXXPYCNJAUFL6LMA&T=C&U=http%3A%2F%2Fwww.amazon.com%2Fdp%2F019531588X%2Fref%3Dpe_147100_25779860_pe_vfe_dt6 (http://www.amazon.com/gp/r.html?R=3E4QRGRIITSRS&C=K0XTUO4Q4AY7&H=PRTHMZ2AJCA1DXXPYCNJAUFL6LMA&T=C&U=http%3A%2F%2Fwww.amazon.com%2Fdp%2F019531588X%2Fref%3Dpe_147100_25779860_pe_vfe_dt6)
Lexington and Concord $13.64
http://www.amazon.com/gp/r.html?R=3E4QRGRIITSRS&C=K0XTUO4Q4AY7&H=SJ8RW0IHCGXYAUDAQABX3KPOABQA&T=C&U=http%3A%2F%2Fwww.amazon.com%2Fdp%2F0393320561%2Fref%3Dpe_147100_25779860_pe_vfe_dt7 (http://www.amazon.com/gp/r.html?R=3E4QRGRIITSRS&C=K0XTUO4Q4AY7&H=SJ8RW0IHCGXYAUDAQABX3KPOABQA&T=C&U=http%3A%2F%2Fwww.amazon.com%2Fdp%2F0393320561%2Fref%3Dpe_147100_25779860_pe_vfe_dt7)
Also cross posted in Deals Forum
number6
Also, for those on a budget, or just looking for a plain good deal, try shopping at www.halfpricebooks.com (click on their "shop online" tab). It's an inexpensive way to stock that library full of all sorts of great books without breaking the bank.