I've considered the 338 Lapua many times for a long range rifle, but can't get on board with the price of ammo. If I were to get into a true long range rifle over my 300wsm that I built, it would have to be a 50bmg simply due to ammo prices & the fact I like to shoot.
I am not sure there is much of a savings there, both ammo's start around $3.00 a round and go up. I don't see either as a daily shooter. It may be different if you are loading your own. I haven't loaded ammo in years and haven't kept up with pricing.