Whenever you're considering a financial choice, you have to try a few what-if scenarios to compare that financial choice to another choice.

A pension is a guaranteed income for life. What is your $11,000 currently doing? What is the range of values it could take on if you left it where it was?

Do you need disability payments? If so, how much would it cost to replace the disability benefit of the pension? Would you be able to save money by cancelling other disability insurance?

Are you planning to retire sooner? If so, what would the difference be in your benefit if you didn't repurchase?

etc. Often a spreadsheet (e.g. Excel) is a good idea for these sorts of things.