Here are 2 online sites with good prices & reasonable shipping for the 10 oz Epsom IT lotion:

bracemart.com or myfootshop.com

Their prices average $8 or $9 per bottle vs. Amazon's $20+$10 shipping each! Shipping (usps priority mail) is a flat $5.95 so for 5 bottles, it would cost $47.25+5.95 @ myfootshop.com for a total of $53.10.