A3-Twenty,
Yes, there are benefits in fuel savings for single engine taxi, Airbus have done a lot of research into fuel economy. May i suggest that their document on fuel economy would be a good read, you can find it here,
http://www.iata.org/NR/ContentConnec...y_Material.pdf
Compared with a 12 minute all engine taxi, a 12 minute taxi of which 8 minutes are engine out, the saving for an A320 is around 50kg. Not large numbers for your one flight, but over a year across the fleet, it is a large saving.
Hope this helps,
high-flyer