Savage,Tikka T3, Browning A-bolt, Remington 700, Ruger 77.
These are the only lefties that I can think of right now.
CZ527, but that's .223 sized cases only. I'd love to see a lefty CZ550.
Weatherby makes a lefty MarkV action but not a Vanguard. I wish they would, I'd be shopping for one too.
But since the Vanguard line was "bargained-down" as the Vanguard 2 (no better fit or finish than the Howa 1500 marked versions) I don't see it happening.
Since you're on a budget, I'd also look at Josh's recommendation of the Savages.
The T3 and 700 will be roughly a hundred or so higher and the A-bolt about another hundred bucks.
All of them are good actions but you just can't beat the bargain you get in a Savage (if you can put up with the UGLY action).
My opinion...They ain't purty but they sure do shoot.