This is a fun challenge in real life so i decided to see iif it will work in FFXI

I start with one 1 gil and trade people stuff of increasing value until i have something worth a good amount of money

For example:
1 gil->a carrot
a carrot-> 1 onion knife
1 onion knife->a scale mail
scale mail-> ....
And so on and so on...

Only rule is i cant throw in extra items, must only be the previous trade