For ideas on coral, frags which are small chunks (maybe an inch average) put on a cap or plug start maybe $3-5 on up to any crazy amount for rare ones, but "normal" easy to grow varieties would be 15 to $20 and then on up around 35-40. If you look at prices sometimes they show a nice piece and then it says $15. "pp" which is per polyp, which is each tiny colorful bit /head or charge per head, so you have to read carefully what you are buying if you are ordering online, and ask if it is for the price is for the piece or the per polyp or head.
You can also join a reef club and they will have swaps and events to buy and door prizes and you could learn a lot.
One other thing is that you need a place to mix up your SW
mix or buy it per gallon and also the ro
water (I think that was mentioned).
Oh, and it is addicting too. lol
Be careful of getting cheap stuff which grows like/are kinda like weeds, Xenia, Kenya trees, Calurpa, Green Star polyps, that all I can think of off the top of my head.
Check out nuisance macroalgae and see what to stay away from as well.
You can do it, just think through it all carefully and have a plan, research. There is SOOOOO much to learn and know. But just like with FW
, you didn't know everything and likely still don't, but now you have an idea what to to do to find out.