How much did it cost for an english citizen to travel by ship to
colonial america in the 17th century?

It would depend a lot on his status/class etc. would he want to
return,  i.e. as a merchant going to arrange exports or as an settler
never to return.
also criminals were transported to the new world as punishment.
Like today a lot of variations,


Kemlo

Quite so.
Here is what one site says, much towards the end of the article:
"But few colonists could finance the cost of passage for themselves
and their families to make a start in the new land. In some cases,
ships' captains received large rewards from the sale of service
contracts for poor migrants, called indentured servants, and every
method from extravagant promises to actual kidnapping was used to take
on as many passengers as their vessels could hold."
http://usinfo.state.gov/products/pubs/histryotln/index.htm

This site says the cost of a passage on the Mayflower (1620) was 5
pounds sterling, equivalent to $1000 in 2004:
http://www.csmonitor.com/2004/1116/p18s02-hfks.html