What would a reasonable price be on an FN commercial 30-06 length action in very good condition?

I'd say anything less than $250...

The other day, there was the FN/Sears/JC Higgins action on Ebay (where you are forbidden to list firearms) and the barrel listed in separate auctions...

Were these barrels really chrome lined?

Anyway, you may be able to contact the seller before the auction gets kicked off the site... Search Mauser.

I like to build on these actions- all the work is already done for you- swept and forged bolt, handy thumb-style safety on the bolt sleeve, one stage trigger, slimmed 2 screw trigger guard, stripper hump milled off, and drilled and tapped... Even if you were to do all the work yourself on a military Mauser for free, you have saved considerable time and effort... I have two on my bench and another at the smiths being tigged up because someone drilled and tapped the rear ring with a swiss army knife corkscrew or something...

Generally around $250. Not only are they a top choice for a custom Mauser but also the best buy.