For the .452 250 grain Gold Dots and 300 grain Deep Curls (excellent deer bullets) I think Graf & Sons has the best deal, with their $4.95 shipping rate. Look here:
http://www.grafs.com/retail/catalog/...yId/559/page/3 They are Item #SP4484 and Item #SP3974, respectively.

I use Harvester short black sabots (H5045SB) for both bullets. They're here at the Graft's site: http://www.grafs.com/retail/catalog/...productId/5481

A box each of fifty 250 grainers and fifty 300 grainers, plus two fifty count packs of sabots is going to cost $50.51, including shipping -$0.51 a shot.

If the 300 grain Jacketed Hollow Point Federal Fusion bullets are Speers, they are not the Gold Dot/Deep Curl models, but the standard .458 45-70 bullets. See them here on the Graf site: http://www.grafs.com/retail/catalog/...roductId/17307

If you want to use a .458 bullet you'll need MMP Orange Sabots. Look here and scroll down to the HPH series. http://www.mmpsabots.com/ Although I've heard that some guys manage to load .458 bullets in the Harvester sabots for .452 bullets, I haven't tried that myself.