Import Tax is a bit of a gamble.....

The Sabertooths (Teeth?) are made by Dimension Engineering who are based in the USA, so make sure you buy from a UK seller, Technobots for instance, although they mostly have the older models.
I personally have received multiple packages from DE and never met import tax.

Also remember the Sabertooth controllers are dual controllers, smaller, lighter, have built in mixing, Li-Po protection and fail safing (as well as a few other things, current limiting, thermal protection, linear control, acceleration ramping.....)