Thanks for the complements.
OK, easy questions first. The doors are hinged. Unfortunately, the frame posts don't line up with the door edges quite right (an oops on my part) so the hinges are slightly visible instead of totally hidden. I just used small, brass hinges.
Money, all in all I spent about $250 for everything (wood, hardware, etc)...not to mention about a thousand dollars in gas going back and forth for that one little peice I always seemed to forget....not to mention returning the things I thought I would need but didn't.
Time:
The frame I built in one evening and then I waterproofed it (about an hour then letting it sit for a day).
A day for fitting, cutting and attaching the oak paneling and making the doors.
An evening attaching the oak trimwork.
One day staining everything (2 coats, 6 hours apart....only took about an hour for a single coat)
And finally about 2 hours attaching the doors.
It will probably take me about 3 hours to make the hood and then the appropriate staining time.
Overall, I started building it on a Friday afternoon, and it was in my living room by the following Wed night. I did this all while moving and unpacking from my apartment to our house (a rather hectic time to do this project....but necessary)
Not sure what you are asking about the top of the stand, the tank sits on the frame that you see in the first pic, I have oak crown moulding that covers the plastic tank frame (the frame is slightly oversized just for that).
As for a simple square stand (not the shape I did....that was a engineering nightmare), I could probably build one in just under a week. $700 sounds a little high, but with him you probably won't find any little imperfections that you can with mine (hard to see but I know they are there). I will probably take some pics of them and post for future stand makers to learn from.