I managed to locate the support page for AOL Desktop, and based on the available data, here's what I was able to extract from the page:
Paid members and some Free members can create up to seven Usernames, including your primary master Username, for your AOL account. The master Username is the one that you first used to sign on to your AOL account. You can create additional Usernames at no extra charge.
As you can see, it all depends on the membership status. It doesn't matter if you are a free or a paid member because the total number of username accounts is the same, just that it differs for some. You should be OK with 5 addresses.