Its not too expensive if you reload. In all reality most people that are hunters don't shoot too much in a year (1 or 2 boxes), so an extra $40 dollars a year in factory ammo for 2 boxes really isnt that much. Keep in mind that weatherby factory ammo is in line with premium offerings from other manufacturer (norma brass etc).
When you are relaoding, the costs are negligible compared to a 25-06 or a 270 (a few cents a round in powder). I have one and love it because it's such a laser. There is a noticeable difference between the 257 roy and the 270 on 200 and 300 yard gongs. It is a fast round.
The catch is that at close ranges the advantages are less pronounced. It is almost TOO fast if there is something at close range.
I was hunting with mine expecting to take a longer shot (200 yds plus) when a deer walked out 55 yards away from me. I shot it once right behind the shoulder and the deer didn't even react. It even kept eating and slowly walking. I had been having a few issues with my scope so I thought maybe the scope was still off. I reloaded and aimed for the shoulder with hopes to plant the deer right there. It hit and flattened the deer right there. When I cleaned the deer, the first shot had hit it's mark and blew up the deer's heart but it didn't even know what happened.
When we skinned the deer the ribs all down the entry side were bloodshot, from the first shot when it entered. It was the most damaged meat I've seen on a deer in quite a while, and this was with Barnes TTSX's