Hi! Well the Ball python is the way to go for a first snake, they tolerate husbandry errors a lot better than most snakes. I agree with you daughter spiders are awesome and have a lot of breeding potential. I paid about 100 bucks for my male a year ago so they aren't that pricey. Although it is nice the idea of taking in an unwanted snake for you first it is better to pick one up from a reputable breeder if you take in a rehome you don't know how well it was cared for. On the point of feeding I have 6 balls at the moment and I feed them all in their tanks. None of them have ever been cage aggressive. I also feed F/T mice I buy in bulk and but them in a box in the main freezer. I would not feed a ball python live because sometimes the snake is not interested in feeding and the mouse/rat will chew the snake and cause injury. There is not a difference in temperament between a male and female, ball pythons are usually docile by nature they tend to hide when provoked or scared. Also about the expense, the biggest part will be incurred during the purchase...the tank, lighting, hides, décor, etc. After that it is all about getting the food which I pay about 30 cents a mouse when I pick them up from expos. If I run out a box of 6 or 4 depending on the size at Petsmart is 6 dollars. Hopefully this helped!