Purchases are on a dialer by dialer basis. If you upgrade one dialer to the Basic plan, it does not upgrade all other dialers to the Basic plan.
All purchases are one-time payments. No monthly fees are charged.
All DialASmile dialers automatically start on the 'Free' plan, and so are available for 3 days after creation.
At any time, you may upgrade a dialer to another plan from the dialer management page.
If you choose to pay for a plan while you still have some uptime left on your dialer, your remaining uptime will be added on to the plan's uptime.