+1 I don't think such a marginal improvement will change anything for you. If it's for rare hills bite the bullet and consider that even old legs can improve with conditioning.

If you're forced into an inadequate bottom gear often, don't work at the edges. Swallow your pride and go for a triple. This may involve some complications and expense, but can give you not only a lower bottom end, but much better selections in the mid range, and might make the whole bike better for you.