So they are probably designed in the U.K., made in the far East (just guessing), shipped back to the U.K., then to the destination country such as the U.S. and Canada. Plus the fact that they are mass produced, but sell no where near the volume of Denon, Yamaha and Pioneer, no wonder they cost so much more.
Of course they most likely put in more expensive components too, such as huge toroidal transformers as others have mentioned. No doubt the T773 is a powerful receiver. I am wondering if a 3805 or 2500, or (635 if you are not in Canada) plus a 2/3 ch power amp is not a viable alternative. Some British magazine reviews don't seem to rate their NAD and Arcam any higher than Denon and Yamaha's 3805, 1500,25000 etc. They rate them all very high but at least one review put the 3805/3910 over the Arcam 300 (can't remember the DVD player model no) combo. It also rated a Yamaha combo over the NAD. Sorry about getting off the topic, just want to share some information I read about these units recently.