Bushmaster br or orc HELP!!!

[Matt parker]

I've recently been looking to purchase an ar 10. I've found that the bushmaster has a few different models, the br and the orc I'm sure there are others but can anyone tell me the difference between these two. I found a br chambered in 308 for 3k and I've also found an orc chambered in 308 for 1900 $. Are theses the same rifles? Trying to do my homework before purchase would appreciate some help, thanks