I received an interesting offer from another company in another city, which pays around £10k a year more than my current job. I like my current job and I am fairly good at it, and my boss knows. However I believe that I am currently underpaid. Looking on the internet, the average salary for my job in UK (excluding London) is around £12k more what I earn now a year. I would rather stay at my current job, but the other option is also interesting, so I used it to try to get a pay rise. I approached my boss and told him that I have another offer and that, even though I like the company, I feel underpaid. He didn't ask how much more they were offering, and I didn't say. Few days later I told me his counter offer, which was "only" £4.5k a year more than what I get now. I told him that the other company still pays more, so I will still consider the other option (I will need to give a final decision in a week, and I told him that). At this point he asked me how much they were offering, and I told him. He said something like "ok, I'll let you know", but didn't look super convinced.
To be honest, I think I would stay at my current job even if he cannot match the £10k more they are offering over there. I would for around £7-8k more, but £4.5k more is too low, considering that I can use this "trick" for a pay rise only once.
I am on holiday for the next week. The other job expect an answer in around a week, so more or less when I am back at work. Please consider that IF at my current job they cannot increase the pay rise, I will happily leave (that is: I am not bluffing).
THE QUESTION:
What should I do if, in a week, he hasn't let me know anything? How should I approach my boss? A) Should I approach him asking "do you think you can get closer to what they are offering"? B) Should I give him the resignation letter directly?
Sorry if I come forward as a greedy person. The two jobs are really similar in terms of what I am gonna do, one of them is closer to home and pays much better, but I know and like the current one - so overall they balance out, a part from the big difference in salary.
NOTE: My boss has a very high position in the company, and thus I strongly believe that he can single handedly decide about my salary.