If you go to .308 you will have access to plenty of cheap surplus ball or even the cheaper plastic rounds.
Look at the Marlin MVP series. They have a Scout version and a Patriot version along with the others.
“If you go to .308 you will have access to plenty of cheap surplus ball or even the cheaper plastic rounds. ...” [Cold Heart, post 9]
Shooters are strongly advised not to fire 7.62mm NATO in US commercial rifles chambered for 308 Winchester. The tow cartridges are only nominally close in dimension, not completely interchangeable. Manufacturing tolerances for military ammunition differ from those for commercial cartridges; depending on country of origin, it is possible to encounter a 7.62mm round that is over maximum size for a commercial 308 rifle. Forcing the bolt closed on an over-max round can set off the primer, especially in an autoloading rifle where the the spring-powered counter-recoil movement can be violent. An out-of-battery ignition is an event to be avoided.
There are other risks.
Much commercial 308 ammunition is loaded to higher pressures and velocities than 7.62mm NATO; firing a 308 from a rifle chambered for the NATO round can result in damage, or reduced service life.
Typically, 7.62mm NATO bullets are fully jacketed and thus not permitted for hunting. A lot of surplus ammunition is loaded with steel-jacketed bullets; they are copper-clad and look no different, but can wear out a commercial rifle barrel more quickly.