If he's a BCI, and I'll leave that up to the experts like Richard, 2-3K grams is average. Males generally are 4-8 pounds or so, although there are exceptions. Females usually 6-8K Grams. The females are much larger.
Regarding the feeding. BCI's have very slow metabolisms compared to colubrids and even some other boids. My 2 year old female is 1K G and eating small rats every two weeks and growing. When I bump her to mediums, she will go to every 3 weeks.
Obesity can happen fast if you are not careful with these guys and it can be lethal. Less is more.
Aside from a strong food response, once out, BCI's are often total puppy dogs. Behira is confident, chill, and calm. Nothing scares her so I never have to worry about a defensive bite. I do have her hook trained. It has worked wonders. A few rubs with the hook and I take her out no problem with my hands.
Once out, she's a total dream.
If you have any inkling of keeping this guy, get a hook and start hook training.
Here's a link to the thread I started on hook training: https://ball-pythons.net/forums/show...=hook+training
Good luck and keep us posted.