ok, with a 50 gallon, have lots of rock, and run tubing throughout the rock for the octo to crawl through and stuff. have all sorts of tunnels and stuff, kinda like a hampster cage would. would a octo like that? like a bimac?
Yeah, the rock alone would be fine, but the transparent tubes would make for good observation, and it might have fun arranging them as it wishes. Just remember you need really strong filtration. Other than tank size, that's the most important part.
Yup, they are proud of them. If you have to buy a new one, don't buy a cheap one. They are worth every penny in the long run. I would still look into finding a local marine aquarium society for used equipment, or maybe even resort to ordering one on Ebay.
There are folks on here that sell baby Bimac's occasionally. Some have eggs right now, the babies won't be ready for a couple of months probably, and after that they will probably have a few left for when your tank is up and ready. You shouldn't worry about that until your tank has been up and running for several months though, it will just make you more eager and make it harder to do the responsible thing.
It's very unlikely that you will find Bimacs available at a LFS, but it's not unheard of. You might ask your LFS if they can special order any octopuses, and they should be able to tell you how much they charge for them. Stay away from "Zebra", Mimic, and Wonderpus though, for multiple reasons. When the time is right, you might also check out some of the online saltwater retail stores like liveaquaria.com and saltwaterfish.com
get the tank first, put some live rock in, let it sit for a couple months whie i look for a skimmer and octo. then after i get a skimmer and have everything, the tank will be ready. all the vids i see online don't show the tanks have much live rock at all. will i only need like 4-5 large rocks?