Upgrade from free version to pro version

I would like to test the plugin out using the free version first.

I have the following question if I upgrade the plugin to pro version:

1) Do I need to uninstall everything before I re-install the pro version?

And since pro version comes with two options (single-site license and unlimited-site license), I also have the following additional questions:

2) If I purchase the single license and later I decide to upgrade to multiple license, do I need to pay only the price difference?
($129 – $69 = $60)

3) Can I use the unlimited-site license to help building membership sites for my clients’ domains?

Thanks

Damen

Hi Damen.

1) Do I need to uninstall everything before I re-install the pro version?

No, you don’t need to uninstall, you’d just add the Pro add-on to your existing s2Member framework.
s2Member® » Pro » Install/Upgrade Instructions

2) If I purchase the single license and later I decide to upgrade to multiple license, do I need to pay only the price difference?

Yes, you’d just pay the difference to upgrade. You’ll find the upgrade link in your Account page.
http://www.s2member.com/account/

3) Can I use the unlimited-site license to help building membership sites for my clients’ domains?

No, it’s unlimited for your own sites, your customers would need their own.
http://www.s2member.com/prices/#s2-terms-license-types

I hope that helps. :)