Im not quoting a Landrover part, I purchased mine from R&E autos, it was a Dayco and came in a box as does the Gates.
I use toothed belts all the time and generally if you get a non stretch toothed belt for less than about $70 to $90 depending on size then you are doing bloody well.
You either have a good mate in the trade or the bloke that sold it to you sold it too cheap as they are much more than $30 at cost.

