Any new (and most used) 7.62 x 51 battle rifles are going to set you back a grand or more. As others here have suggested, you can still find good values in the AK variants, with plentiful ammo, and an ever increasing volume of aftermarket/custom accessories. That gets you a 7.62 x 39, which ballistically is not really all that different from your .30-30.
If you're willing to go down to 5.56 and have the time and willingness to shop around, you can purchase the receiver, upper and components and build a custom rifle from the ground up. If you want something out of the box, take a look at S&W's M&P-15. The base model is pretty decent value with an MSRP of $739.