Or perhaps, I can't really come (for external reasons) but if you were to tell me that 10-15 people who I really want to meet will be there and it won't be too far away from me then I might put it on top of the list.
If you were to tell me that 3-4 people were gonna be there and it is going to be 1 hour away from me I will not come.
I disagree with your comparision completely but agree with your point.