Depends on which country you are in - they are no where near as expensive on that for your "average" killi in the UK.
My Aphyosemion australe I got from BigC got on really well with my small community fish (I wouldn't keep them with territorial or much larger and faster fish than themselves). Lots of plants and some low light would be good to.
But BigC is the man to speak to for tips !
Hi,
The link below is from the AKA (American Killifish Association) beginners section. You might find some useful info here rather than me writing a four page essay. If you need to know something specific then please feel free to ask. http/aka.org/modules/tinycontent0/index.php?id=4
Regards
BigC
P.s. A nice little inexpensive book for beginners that I would recommend is Killifish: A Complete Pet Owner's Manual by Steffen Hellner http/www.killi.co.uk/bookDisplay.php?bookID=3
Killifish are not expensive unless you wish to aquire more rare exotic types like Diapterons. Its knowing where to look and who to see. One tip I would pass onto the novice is crawl before you walk. Certain species of Killifish are much much harder to maintain than others and the novice can be put off by aquireing stock of that nature with no experience of keeping the easier varieties thus suffering setback after setback and becomming disillusioned with the idea of keeping these little gems.