if bitcoin forks there won't be two coins. there will be 1 coin.
if bitcoin splits there may be more than one coin. only if the other chain can stay alive. another chain with low hashrate will be weak. susceptible against attacks and can die easily.

if it can stay alive and if it can gain enough support,.... then it has to be listed on exchanges then people have to panic sell on there because you know they have gotten some free coins they want to dump. then things have to calm down, .... and a lot more. then price will be determined. it will surely be a lot less than now.