Fish only tank
This may sound like heresay to some but I had a couple of fish only saltwater tanks that worked well for several years.
If you go fish only (i.e. no corals, no anenomes, no liverock,etc) it's much easier.
I used undergravel filtration only. 10% biweekly water changes, simple flourescent lighting. That's all you need for happy fish. A few DEAD corals or pieces of baserock for decoration/hiding places.
If, on the other hand, you try and recreate a reef in your living room, costs will go through the roof!
The other key benefit of fish only is that WHEN (not IF) your fish come down with a case of saltwater ick (parasites) you can easily cure them with copper. Copper is awesome stuff because trace amounts kill invertabrates but it's harmless to fish.
Oh ya, obviously if you have a simple filtration system, don't overwhelm it with too many fish. I had a 55 gallon which was shared by a Triggerfish and a Lionfish. Those two coexisted for over 5 years and were very entertaining. Talk about a feeding frenzy when a hapless handful of goldfish were dropped in.
I throw this out there as an option to consider if you'd just like to enjoy some interesting and colorful saltwater fish w/o going crazy with the expense.