Help - Calculate cost of pension contribution?

Hi,
In a quandry and need some assistance. Just received two job offers, both offering same salary. One offering 8% pension contribution (DC),
the other offering 5%. This delta accounts for €2,200. As a negotiating point, how much would I need in extra base salary to allow me fund this difference myself? Thanks in advance, apple1.

Just €2,200 because if you put that in as a personal contribution in the "worse" situation then it will not be taxable, and you will have the same amount going in to your pension as in the "better" situation.