Because of this, Clove UK sensed the opportunity and is now selling spare batteries for the Samsung Galaxy S. They cost $34 (or £20 ) a piece and you can order them from the link below.
source: Clove UK
1. Univice (Posts: 38; Member since: 15 Jun 2010)
Haven't checked recently but I got an extra Samsung brand battery for my Galaxy S Captivate at Amazon.com a few months ago for $16. It was cheaper than the other brand they offered.