You could always try to find a bargain on craigslist. 3 and 6 gallons for SW
is especially hard for beginners. You have such a small volume of water that if you were to make a mistake like add too much salt or overfeed, there would be major consequences. In a larger tank like a 55 or 70, the system would be more forgiving so to speak. I recommmend a 10 or 20 which will probably not break your budget.
For filtration you can have a simple HOB
filter (aquaclear is a great/popular brand, and it's recommended to have a filter double what it's rated for saltwater. So a 55g filter for a 20..you don't have to do this though.) Lighting you can use power compacts or a 2 bulb T5 HO
light would work (are about $100). One option could be Odyssea lights which are cheap, but they aren't great quality and heat up a lot. You can also buy all base rock which is a lot cheaper than LR
. Or you could buy mostly base rock and some LR
to seed it. Having all LR
is great, but it costs generally $3-5 per pound and 1-2 lbs per gallon is recommended so that can get costly. Good luck