IETF registration fee?

[Paul Aitken]

Can you help me understand why the One Day Pass rate ($350) is so high 
compared with the full week rate ($650 / $800)?

Registering for two days could cost more than a week!
Surely the day rate should be a little more than (week/5), eg about $175 
- $200, to encourage those who only want/need to contribute on 
particular days?

Thanks,
P.