I have heaps of rifles in both calibres. My license plates are SP3006 and my initials are MM, as you can see I have a liking for the old warhorse. Having said that, I will be the first to admit that every 308 I have owned has been very accurate, moreso that the 3006, but they have been acceptable also.
I think the only advantage the 3006 has over the 308 (apart from a bit of old 'warhorse' cred) is the fact that it can handle heavier bullets well. Load the 308 with premium bullets and the big game is in peril.
I'd buy the first one that comes up unless you are going to be shooting elk all the time. If he has a 308 on the shelf, whine that you really wanted a 3006 and vice versa, There is generally not much fat inthese deals to be bargaining though. Don't take the package scope, always spring for a better quality one and you will enjoy the better perfoemance over the years. I'd rather go with a second hand Leupold than a new Tasco, have a sniff around the shop and see what is there. I picked up a M8 6X Leupold the other day for not much more than a new Tasco. Like the Rolls Royce salesmen used to say, "The quality is appreciated, long after the price is forgotten." Tat goes with Leupolds as well.