After accepting the Ferian mission %reward% shows in the Missions screen.
Needs

reward: (fmtCurrency 'credit (msnGetData gSource 'reward))

in <Text id="descSummary">
Line 142.

Also the targetName and reward data may not be needed in Text ids Intro and InProgress.

PS Seeing the reward stored in a marker has helped me in a mod too, thanks.