hello, it seems that Blaser is one heck of a rifle. BUT they come with one heck of a price tag too. This would be just short of a total waste of money in my humble opinion. You can have a custom build by a good smith, a Nightforce scope mounted on top, and have money left over to purchase reloading equipment with the money you would have spent on just the blaser.
Start with a good custom action, give Joel Russo a call for the stock, and I'm sure that there are a few good smiths in your neck of the woods to put 'er together for you.
However, If you are just getting into the sport, you may want to just start out with a good factory rifle to get some practice in and stretch you legs so to speak before you spend lots of money. You never know, you may find that you are more interested in a different caliber.
As for the 308... excellent target cartridge. It will last thousands of rounds provided you don't let it get too hot and there is lots of factory matchgrade ammo out there. However, It is a little weak for 1500 yard shooting. If you are punching paper you won't need much more, but if you are taking game you will have better luck with something a little bigger. What do you intend to do with the rifle? do you reload?
answer a couple questions and I'm sure you will get many many more opinion.