peterchen: Yes you are. What bothers me is control elements' reaction to user's actions. I'm not sure, that showing block with payment methods on input focus is a good practice.

Firstly thank you very much for feedback. I realize, that there is no "correct answer" I asked the querstion to gather your opinion on a particular pattern. The pattern I shared with you here is just at "an early PSD stage", it will be up to my client to use or not to use such layout and behaviour. So no A/B-test is possible. I just wonder if you have any alternative to my solution in mind.