Hi,
I think it could be better if we can set an incremental range for an action product,
I mean, for example, if the start price is 100000, I should be able to set a range, for example : 5, then user can offer prices like 100005, 100010, not prices like 100001

is there any option like that I missed ? or it should be developed?

This is feature not available, need to be developed.
Thank you for suggestion and creating work item at GitHub.