I'm assuming that these amazing prices on the 10" dobs are somehow a "stock issue" or an importing "numbers game", as opposed to a reflection on the actual manufacturing cost. Keep in mind that the $249 6" comes with a R&P focuser, compare that with $399 for a 10" with Crayford.
I must admit I'm stuffed if I know how Lee can sell them at that price, I'm just mighty pleased to hear he is.
These prices almost certainly won't last, the stock definitely won't so for anyone considering this I'd grab the phone number off the website (they don't do internet trade or list an email address) and ring them at opening time tomorrow morning!
I just wish I had a few hundred bucks spare on my credit card right now, I'd have a set of 10" binoculars quicker than you could say "collimate"!
(... but no, I had to be sensible and have my brake pads replaced, discs machined, LPG convertor replaced, engine tuned, etc, etc. See what you get for doing the right thing??)