Milk are very easy to care for also I would not recommend a hot spot higher than 83/85 at the very most, as far as cool side they will do very well at ambient temps.
as far as cost price vary depending on the morph however even DH recessive are very affordable.
Temperament gets better as they age when they are young they are what I call "wild childs" they might musk or bite but it goes away very quickly with regular handling.
I love honduran milksnakes they are very colorful and have a great temperament.