I have a line on an L61R. I believe this is a pre-Garcia action as it has the exposed firing pin assy, not the AV style shroud. The action is brand new and has never had a barrel threaded into it. I'm thinking of building a .280 on it. How does this action stack up to an L579, ot the than being a long action?

What would be a fair price?

That would be a nice action for a 280.
$500.00 is fair, but people are getting a bit more these days.
lawndart

A virgin L61R is quite a find. Check to see if it has the "third" or "safety" lug just in front of the bolt handle (like a '98 Mauser). The Garcias and some Stoegers were also made without the shroud, so having an exposed striker assembly doesn't really tell you much. A "pre-Garcia" is somewhat more desirable (to me) in a finished rifle, but there is absolutely nothing wrong with the "Garcia" or Stoeger era import actions.

The L61R is essentially just a full length L579, with the exception of the "third" lug on the early models.

As to price, it seems to me that people are willing to pay way too much for bare actions as compared to "donor" rifles. You might find a beat up L61R rifle for as little as $500, and it would have some salvage in the barrel and maybe the stock, not to mention a scope or mounts. At any rate, the action you "have a line on" would make you a dandy custom rifle.