See the following from the Power Store FAQ page:
A: Yes, you can save the most if you buy multiple licenses at once as we offer 10% off two licenses, 20% off three licenses and so on - up to 50% off six or more licenses. Or if you prefer to only buy one license at a time, you can save 10% off when when you buy the second license, 20% off when you buy the third license, and so on - up to 50% off. Please email us at sales[@]webassist[dot]com or call us at (888) 490-1545 ext. 2 in order to receive your discount.
if you have further questions about power store licensing, please send an email to the sales department at firstname.lastname@example.org