My advice to anyone wanting to buy a Sako Quad is-don't unless you really do intend to use different barrels. Even then think very hard before you do. I tested a Sako Quad in .22 LR and was underwhelmed with the build quality and the cartridge eject although this was probably because the rifle hadn't been used for some time. The point to make is that this rifle came out AFTER Sako discontinued the superb Finnfire and it is just not in the same class. The interchangeable barrel is just a gimmick in my view anyway.
The rifles you should look at for this sort of money (over £500 new) are the Anschutz, the Sako Finnfire-if you can find one at sensible money-and my personal choice the Weihrauch HW60J. All three are excellent rifles but to me the HW trigger is up there with the excellent Anschutz unit -which sets the standard by which triggers are judged- and certainly better than the Sako. The clincher is that the 60J comes at a usefully lower price. After extensive searching to treat myself to a 'lifetime rifle' I paid £450 for my 60J 'mint used' and am delighted with it. If an Anschutz had turned up first with a nice stock at the right price I would've bought that but not the Quad.