Also, usually 2-3 inches is big enough to sell. Depends if you are going to post them or have them collected. When posting Axolotl its strongly advised to use a polystyrene box with a plastic bag inside half water half air with the bag large enough to fill the box so it has no movement. Then place that polystyrene box inside a carboard box padded with packaging paper or bubble wrap. You can also put ice cubes in ziplock bags around the bag which holds the Axolotl to try keep the water as cool as possible during transport. I have posted 2 inch Axolotls via post with no issue, just always use special delivery to get them there fast, state they are live fry, and plaster the final box you post with fragile marked packaging tape to make courier workers aware to be careful.
I'd always feel safer with collection though
I just put 7 of my biggest, healthiest babies in Un dechlorinated water. Basically I forgot to put it in, what happened was I normally dechlorinate the water in the bathroom but today thought I'd do it in my bedroom as my baby sister was upstairs. I completely forgot and was doing a part water change. I siphoned the waste out like usual and then refilled what I'd taken out (not much ) with Un dechlorinated water 
