I am looking to install ACT! by Sage 2009 (Version 11.0 - Multi-User 5-Pack OEM) on a Windows Small Business Server. Is there any reason I can't buy two 5-Packs and so everyone will be able to access the same database.
Keep in mind that for Act! (as opposed to Act! Premium) there is an absolute limit of 10 users for a database. If you are already at or close to having 10 users, it likely makes more sense to go with Premium so as to allow for future growth. If you stay with Act! and then need to add an 11th user, you will be required to buy 11 upgrades licenses of Premium, and your initial savings are long gone.