I bought my nurse shark from a LFS
for 199$ it was about 10 inches long! Not sure what they cost now or even then. Bought it on a whim kinda. My tank was six feet long had three other fish in there with him.
Had it for about a year he grew like crazy. They said to not feed him as often to keep that from happening but seemed mean to me to let it be hungry. He was about 18 inches long when i took him to the LFS
that i did almost all my dealings with and he gave me store credit for him. He had a huge tank to keep him in. It was like 10' by 10' about 18'' deep. He kept him there for a few years. He lived just fine for me. I wouldn't recommend the eggs i tried that twice with no luck.
If you go with a bamboo or similar just buy one already born and swimming and eating good.
My opinion on it is there all mostly small when there born so as long as you had a 125-150 gallon you could keep what you want. The size of the tank will only factor how long you can keep him. That being said jut because there small at birth or whatever i would recommend even thinking shark of any kind with out at minimum 125gal. But be prepared to have to get it out and have a place to take it!