There are a few different types of .243/6.5mm cartridges out there. They're generally best suited as varmint rounds, but can be used on medium sized game, provided the shooter has the appropriate amount of skill.
80's or so
early 80's
you should pay about 300 to about 350 dollars for a Remington 243 rifle
Late 60's to early 70's
Depends on if that model is offered in 243
Because that's what the bore measured out to.
Great rifle.
50-400 usd
Varmits to deer.
The .243. It's basically a necked down .308 Winchester.
That depends on the exact model of rifle.
500