1 year old ball python size.

I recently bought 4, july 08 ball pythons all right around 300 grams. I know this is underweight, they dont look too bad, just a little skinny. He said they were all eating live mice (for some reason). I thought maybe they were picky eaters, but nope.. I have been feeding them f/t rats every 3-4 days since i got them and they are almost always hitting them without hesitation. I can already see a noticable size difference in just 1 month. It makes me wonder how this happens. Do breeders not feed the offspring that they are going to sell very often to save on feeders? I would think it would be worth it since bigger balls are usually worth more.. Does anyone have experiences similar to this? I heard ball pythons grow the most in the first year of their lives. Does this mean they are going to take alot longer to get big?
Just seems strange, thought I would share whats going through my mind right now..

That weight doesn't sound too off my male is 08 and when I got him was 215grams and wasn't skinny at all. All snakes grow at different weights.

goodluck with them

They are going to very I have 2008's that are 900 grams and I have 2008's that are 150. As long as your offering the right food the animal will grow at its pace.