Retirement work savings

My wife and I just retired last June. She just turned 60 and I will turn 59 soon. We own our home and cars, we have no credit card debt and our savings (not including retirement accounts) is almost $100,000. Our kids both finished college without accruing debt (thank you very much!). As I completed our taxes this spring, the amount owed is almost $2,400. If we open an IRA for $8,000, the amount owed drops to under $1,200. Does it make sense for us, at this point in our lives, to invest in the IRA for the tax savings? Part of me says it is a no-brainer; the other part says that investing in an IRA when you are already retired doesn't pass the common sense test. What do you think? Mike, Blue Earth, MN