Software as A Service Lifetime Subscription Asset or Expense?

I’m looking at buying some WordPress plugins which are generally software as a service with an annual subscription. Some of the plugins, however have a lifetime subscription option for a lifetime subscription update.

The annual subscription I would normally book as a prepaid expense reducing the value over 12 months. But if it’s a lifetime purchase, would this be an asset or 1 time expense? If it’s an expense which asset classes they fall into if they are not systems software and:

1) It is less than $500 CAD?
2) It is greater than or equal to $500 CAD?

I just don’t find that examples the CRA docs give provide enough clarity for this type of situation.

Thanks in advance