I just bought a couple of phone batteries for my very old Ericsson T29S, from
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWNX:IT&item=320293795383

I will be paying 19.74 EUR for the two batteries, delivered from Hong Kong to Portugal.

The price is computed this way:
2x 1200 Mah batteries = 12.82 USD
delivery = 11.50 USD
optional insurance = 1.50 USD
total = 25.82 USD
eBay/Paypal EUR/USD exchange rate = 1.30820

So, in euros, I’ll be paying 25.82/1.30820 = 19.737 euros = 19.74 euros.

The interesting part is the EUR/USD that eBay and Paypal used: 1.30820.

Ebay_paypal_eur_usd_on_20090111

This value has no relation with the real EUR/USD in the past 5 days

Eur_usd_5days_20090111

Check http://finance.yahoo.com/q?s=EURUSD=X for tracking these currencies.
Check http://www.xe.com for the realtime EUR/USD relation.