How many mice?

[dangernoodles]

Hello all!
In the near future I plan to purchase a captive-bred baby ball python.
I am going to buy hopper mice from PerfectPrey, but wondering how much I should buy.
I want the mice to last one year, but I understand this is unrealistic.

Buying a 50 pack of mice would be much cheaper, however I would have to throw it out if it got rotten, since it can last probably 6 months in the freezer.
But if my snake grows, I could feed it more than one mouse meet its nutritional needs, so I could use up the package.
Buying in larger quantities is often usually is for if you have more than one snake.

Buying a 25 pack of mice would be more expensive, since I would have to replace it, and buying in bulk is cheaper. However, I could make good use of the mice and use them all up.

Please let me know your insight!