I'm sure it's not the best but I've been shooting a Rem 700 30-06 for 20 years. I like the 700 so much that I bought a 300 mag in the model 700 a couple years ago too. You can still find Remington models 740/742/7400's and they are semi auto and browning of course makes one. I don't know much about the Browning but the Remington's have had some issues with feeding.
I'm not sure, it seems a little high. I bought a 742 in .243 with a scope a couple years ago from a guy for $250. I ended up trading it off, it was just too heavy compared to my bolt or lever actions. I'd check gunbroker and some places like that before shelling out the cash.
If I were to go semi-auto, I'd probably pick a Browning BAR; reliable, proven and easier to mount a scope than the Garand. For a factory bolt, Savage, which has at least a dozen models to choose from depending on your intended purpose. But really unless you need competion level accuracy there are a ton of good options that will shoot within 1/2 MOA of each other. And if it is for competition, .30-06 usually isn't the first choice of cartridge.