This is free for life and has all of the features except those in the Premium level. (see Premium features here)
Regular users get up to 25 Contacts and 25 Companies.
You can import more as a Premium user, but when your account goes to the Regular level you won't be able to add any more if you are over the limit.
However even if you are over the limit you can edit, add Log Entries, associate to Companies and Jobs, etc. In other words, if you import 10,000 Contacts when you are Premium (even if it is the premium trial), you will be able to fully use all of the records you have imported, even though it is over the Regular limit.
Cost: $ 0