Will I be charged on activation or completion?

Fees are only applicable at the time of subscription/renewal. The price is 160 USD per label for a first bundle of 40 TLDs. 
Note that the price is susceptible to increase when more TLDs are added to the coverage.

FAQ

API (Automated Interface)

billing

correction process

general

mark record verification

Notifications

official agents

proof of use

Registrars

Registries

Signed Mark Data (SMD)

Strawman Model - Abused Labels

Sunrise Services

support

trademark claims services

Trademark Eligibility Requirements

trademark submission

TREx Service

user registration