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 43 TLDs. 
Note that the price is susceptible to increase when more TLDs are added to the coverage.

FAQ

API (Automated Interface)

billing

Brandpulse

correction process

documentary evidence

general

invoicing

Mark Record Transfer

mark record verification

New gTLD program

Notifications

official agents

online payment

OT&E

prepayment account

pricing

proof of use

Registrars

Registries

Renewal

Signed Mark Data (SMD)

Strawman Model - Abused Labels

Sunrise Services

support

trademark claims services

Trademark Eligibility Requirements

trademark submission

TREx Service

user registration