It seems like a specialise and high risk business to me. You would have a hard time swifting out the demand. Once you know that you may not have the skills for it as you are most likely zero knoledge on the technial skills. These are reasons enough for me to avoid it.

Well start up cost depends on what you are looking at. Dragon fish, jap coil are also deem as exotic. Cost varies with what pets you are keeping. If it is also you own pet, then is best to start as a home business.

I had a freind who sells puppies (that looks like pikinese dogs with a Japanese sounding name). It took him a while to get a b****. Once he got that he turn it into a business. After mating season he will put up pictures to sell the puppies. It is still a home business for him today.