$65/200 factory rounds you say? That's $32.50 per hundred.
Let's assume you get the brass for free, and the powder for $30. at 25 grains, that's 11c per charge, plus 3c for a primer and 20c for a premium vmax bullet. 34c each or $34 per 100.
Hornady 'varmint express' premium varmint ammo runs $17.99 per 20 or $89.95 per hundred.
Compare apples to apples.
Load surplus powder, and we're down to ~8c per charge, and surplus pulled FMJ's for 10c each, and you're at 21c a round, or $21/hundred.
So, the cost savings are higher with premium loads than FMJ's. That's to be expected, but the performance of premiums on varmints is an order of magnitude better.
Or, put another way, you can load premium ammo for the price of surplus.
Anyway you cut it, your cost savings will depend on how much you shoot. For a few hundred rounds of FMJ, it's hard to justify the expense of equipment. For thousands, or for premium - it gets a whole lot easier.
What this all adds up to - you'll probably continue to spend your existing budget on ammo - you'll spend the same amount. But you'll find that you end up with more ammo for your buck than before. Spend a hundred bucks for a hundred rounds, vs spend a hundred bucks for three hundred rounds.