Varying Amount for the application Paid

Hi

I'm wondering where the differences in the Amount for the same app are coming from?

Example from my application (I entered 10.00 in the amount field):
05.11.09 - Payment fee: $0.69 USD Net amount: $7.31 USD Total: $8.00 USD
12.11.09 - Payment fee: $0.59 USD Net amount: $9.41 USD Total: $10.00 USD
20.11.09 - Payment fee: $0.69 USD Net amount: $7.93 USD Total: $8.62 USD

Another Example (I did set the price to 1.00):
24.11.09 - Payment fee: $0.10 USD Net amount: $0.90 USD Total: $1.00 USD
26.11.09 - Payment fee: $0.11 USD Net amount: $0.89 USD Total: $1.00 USD
28.11.09 - Payment fee: $0.11 USD Net amount: $0.89 USD Total: $1.00 USD
02.12.09 - Payment fee: $0.11 USD Net amount: $0.69 USD Total: $0.80 USD

From the first example The total price of my app varies between 8$ and 10$ and in the second it varies between 1$ and 80 cent, my incomings varies between 7.31$ and 9.41$ in the first and between 69 cent and 90 cent.

How does this come?
My only though is that it could come from currency exchange wehre my application is just presented for 10 for all currencies...

Variations due to payment method, sales taxes

These maybe due to the payment method user has opted to use. See http://slideme.org/rate-schedule

Also in some countries you have differences in sales taxes and VAT.
http://slideme.org/faq/developers/why-are-taxes-deducted-my-applications...

Ok, thx for the Answer

Ok, thx for the Answer