That makes sense! That also explains why guys are hesistant to call many girls to find out who can offer the best deal for him, or why some guys wont call a girl even if they think she is pretty.Think of it from a Japanese cultural perspective...the Japanese don't have a negotiation culture and also have a culture around face...so offering lots of money for extra services means it eliminates the inherent conflict of a negotiation and means you are likely to say yes which eliminates or reduces the chances of a rejection (which presumably would be shameful).
Guys also avoid calling girls who are together with their friends, probably because they are intimidated and think those girls didn't come there to go out. Some of the girls i know in cafe will be ok to chat with me, but some will tell me to not talk to them, and say that they will hang out with me some other time but that they are there to find guys and that they think they wont get called if we are talking.
A good number of the Japanese guys are definitely very nervous about calling a girl and it not working out.