ContactWorld pricing is based on different packs depending on what you need; just pick which is best for you and then add premium support and bolt-ons as required.

"ContactWorld for Salesforce enables all incoming enquiries to be dealt with by Future Leader's own expert staff, and means we now have a really easy way of recording every call that was made. We also now have the ability to easily monitor how long calls take, how many calls a day and it's all going into Salesforce."
Shirley Gaynor, Chief Operating Officer, Future Leaders