I'm still in the process of setting up my nano reef. With me having a good source of used equipment and low price fish it's really not bad at all to keep a saltwater aquarium. The only issue is with the high entry cost. Live rock will burn an unimaginably large hole in your pocket, I payed up to $7/lb for my fully cured live rock. Salt isn't terribly expensive either figuring you want a 10% - 20% at most water change weekly. But maintenance fees go up HUGE when you go for a larger tank. With my 20g I will be going through about $2 a week in salt.. if that. Then $7 per pack of frozen food which will probably last me 4 weeks once I get my tank stocked up. Really the big expenses aside from live rock come when you decide to go high tech with the saltwater setup to make your life a little easier.