Assuming the breeder makes sure the snake is feeding before selling, what is the typical size of the snake at this point? I'm pretty sure I've seen people mention this as being about 150 grams, but I'm not certain.

If that is the case, is there a reason to not start out right away with pinky rats @ 6-8 g each, or smaller fuzzies at 9-15 grams? Or are these rats usually too big in size, despite the weight being around 10% of the snake's weight?

I ask because everyone says make the switch from mice to rats as quickly as possible, so I'm not sure why you'd even start with mice if there are appropriate sized rats available (assuming, of course, you can get the snake to eat the rats).

I've never bought rodents, so I don't know how the weight correlates to the size, and I wouldn't want to buy a bunch of f/t mice at an expo, end up buying too many, and having leftovers when the snake was ready for rats. Seems to make more sense to me to buy the right amount and type of feeders to get me through each stage of prey sizes right off the bat.