Well, trying to tell you how much a saltwater fish would be would be impossible without knowing the species as they can run between $3 and $300. Most of the fish that would live in a 10g tank wouldn't be too expensive, though.
I have no idea how much lighting would cost for that size tank. It would be alot more expensive if you were looking for a lighting fixture capable of supporting coral. I have a 36" fixture that the bulb burt out on, a new one is like $45 for the bulb.
I would suggest slightly more than 10lbs of LR. For smaller tanks, generally it is more than 1lb per 1g.
Keep in mind that SW evaporates faster than FW, so you would need to do more WC than usual.
You could try looking on Craigslist for a complete setup. I got my complete 30g setup w/ stand, 10g sump, half a bag of salt, and a bunch of fish food, all for $150. My several month search finally paid off!