Since you're an individual do you only pay $5/mo as 1 user? Also, do you have multiple accounts as one user or how exactly are you setting that up?
Now its $5 per account. An account being in Googles own words:
"We consider a user to be the same as the number of distinct email inboxes you need. One user can have multiple email addresses, and a domain can have multiple aliases – these are included in the price for each user."
Check out all the info you need at: http://www.google.com/enterprise/apps/business/pricing.html