Depends on what you are using it for. Both will kill small to medium size game within their limits.
Not always. The gun should be selected for the purpose it is to be used.
200
plenty
want ad, gun show, gun shop
243
50-200
Probably the 300 is going to give you better performance when it comes to accuracy. I sure am a fan of the 3030 as a nice lever gun though.
100-1000 USD or so
Well, it is a rifle, but dozens of companies make rifles in .243 caliber.
Mild recoil
Yes
A rifle.