Keep in mind that big brands like Massey, John Deere, New Holland and a couple more, just get their tractors built by companies like Tym, LS and some will get built by Branson. So when you buy one of these big brand tractors, you pretty much pay for the brand, hence the price difference. Of course, this big brands won't disclose this info to the public.
As an example, the Boomer series of New Holland is built by LS and it is exactly the same as LS tractors apart from the hood and the price. Branson builds a couple of series for John Deere, I believe the 5E and another that I can't remember. At least for the European market.
Also consider taking a look at Branson tractors if you have a dealer close by. It's an heavier duty tractor than most brands. I was bit sceptic when I got mine, but after owning it and take a closer look at it, I can see it is built better than big name brands.