How many rounds fired, what accessories does it come with, overall condition...?
If it's in like new condition, 100 rounds or less fired through it, I can see $2,500 as a good price. $2,000 a great price and if it's lower than that, you're stealing it and you need to get it in your hands as fast as possible!
If it's been used regularly and has 800+ rounds fired through it, maybe some signs of use... I would offer less than $2K for it, if the owner doesn't like it, walk away.
Here's the big problem, LAR went out of business and you'll never get any replacement parts for it, ever! So if you break something, you'll have to have them custom made.
For you that could be a plus in negotiating on the price, more so if the rifle isn't in that good of condition. So, something else to think about when buying one or when it comes time to sell it.
It always reminded me of the Maadi Griffin and the muzzle break is worthless, first thing I would upgrade. Either one from Serbu or Armalite but WAIT... there's more! LAR used a different thread pitch, so you'll have to make sure that they can make you one.
I know Serbu can but you'll have to wait a little bit, Armalite might, I've seen one on a Griz before but not sure if it was rethreaded or not. So you'll have to make some calls to find out who can make it happen.
Lastly and this comes as a warning, DO NOT MESS WITH THE TRIGGER, EVER! It's a shell holder design and only the manufacturer should adjust them. There's been a couple accidents over the years and it came back to the owner fiddling with the trigger. So just don't, seriously!