It's hard to say what it would cost per month or year... There are a ton of factors to think of. By what it costs per month or year I assume we are leaving out things like tanks, air pumps, heaters, etc and only factoring in things like food, water, and electricity?
There are a lot of ways you can save money so that you don't end up dropping a thousand dollars-
- Buy tanks from second hand stores or on kijiji (Craigslist). Keep petco 1$/g sale in mind.
- Buy heaters, pumps, filters, foods and cultures etc online. Amazon has tons of amazing deals.
- If you can do it yourself, do it. uarujoey on youtube has some great videos.
- To jar fish you can be creative and use 2L pop bottles with the top cut off. Not pretty but cheap and effective.
- Forums like this one are a great place to get plants and sometimes fish for good prices.
Hope that helped a bit. Be prepared to spend a good amount of money on a high quality breeding pair, and its important not to compromise in this area.