There are many good nano all-in-one tanks out there and there are many 'bad' tanks (the same ones that are the good ones) available. It all depends on what you want to keep and especially on your commitment to keeping anything alive in them.
Though theyar e know as all-in-one tanks, you still have to dedicate a certain amount of time each day to upkeep. There are no 'do-it-for-you ' tanks.
You probably all ready know this,and if you are new to nanos but not to reef keeping, then it would probably be best to know before hand what youa re wanting to keep, what you hope your set-up to be in 6-12 months from now.
The lighting is probablyh the most important item as most all the all-in-one tnaks have adequate filteration (witha little modifying).
If t=yor are new to reefkeeping it might be best to find one that is simple and concentrate on NOT OVERSTOCKING.
Nanos are difficult for the most part. Theya re not a tank you can place on your desk top and fill with water and corals, fish and inverts and look all pretty without much attention and knowledge in reefkeeping.
Most end up full of algae, dead and dieing fish and corals and the owner pulling their hair out wishing they had never seen a nano tank.
Go online and do some research, which is exactly what you are doing here-good job BTW-but most important, ask yourself what you want the nano to do for you. What are you wanting to keep?
Clams? PC lighting is out. MH not cheap and probably need a chiller.
Mushrooms and zoanthids? PC lighting OK. Lots of fish? Nano out. 55gl or more.
I almost forgot your question. You get what you pay for. Buy cheap and get cheap. They are all about the same as far as price for what you get.
Some do have more problems then others. To get a good system in the 20gl+ range with good lighting, you are looking at around $500 starting with added pumps, etc.
