The challenger kit is better than the anniversary kit, better stronger O-press.
$299 from Gunworks.
Ditto to the positive comments on the lee loader kits. Except if you are wanting to start with both .308 and .303 or larger volumes then a press and die kit is the way to go.
I do wonder why you want to go for both .303 and .308 if you are wanting to reload. You can make handloads to suit all your needs with either calibre. Sell your .303 or your .308 and buy reloading gear for the remaining occupant in your safe.