That trigger is primarily for subscription status change and the basket info is only available through an API call so can't be substituted in. For the usage you're wanting I suggest a CB Query Field with the below query. This should pull all the users donations and display them as a field on their profile dynamically so you don't need to worry about a field being up to date, etc..
Code:
SELECT SUM( `amount` )
FROM `#__cbsubs_donations`
WHERE `status` = 'A'
AND `user_id` = '[user_id]'
That'll add together all the donations the user has made (regardless of the donation plan) that are active (paid). You can also filter it down to only add together specific donation plans with the below usage.
Code:
SELECT SUM( `amount` )
FROM `#__cbsubs_donations`
WHERE `status` = 'A'
AND `user_id` = '[user_id]'
AND `plan_id` = PLAN_ID_HERE
krileon
