Powerboost 500 USB lipo charger

Just a quick one.

I've bought a Powerboost 500 USB lipo charger and 5v boost regulator for my Arduino Pro Mini project.

But I find the unit a bit expensive. Nearly £20 incl postage!

Are there any comparable units out there for less?

thnx

If I knew what the specification of a "Powerboost 500 USB lipo charger and 5v boost regulator" was it might be easier to suggest something comparable.

Steve