could it be
money
My first is in a bank,
Money is in the bank
My second is an evergreen,
US dollars are green
My third is for your benefit
Everyone likes having money
My fourth is in a store,
you by stuff at stores with money
My fifth is identical,
Abraham Lincoln is on the five dollar bill and one cent coin
If you've found the pattern What is my sixth?
not sure what the sixth would be, possibly the $100 dollar bill
Nine is the limit,
could refer to the people on the bills and coins not repeated and found in general circulation. i.e. not the $1 coin or $500/$2 bill
My other idea could be
the Nine planetary limits but I can't figure out how to relate the clues
