Shared starts at US$ 6.25 a month for 10 addresses, and three customers at most use the same address at the same time.
Dedicated starts at US$ 6.25 a month for 5 addresses. The address is yours alone for as long as the plan lasts, and nobody shares its traffic.
The choice between the two is a matter of account: if you need the address for yourself alone, and the whole traffic, go dedicated. If you want the lowest price per address and can share with up to three customers, go shared.
The price is for the package, per month. Ten dedicated addresses cost US$ 12.50 a month. A quarter, a half year and a year cost less than twelve times the month, and each period is listed on the pricing page.