No, I don't believe buying the deluxe version will find any more money for you. What I would do is get out last year's return and compare it line by line with this year's and see if you are missing anything.
I don't know if you have children or not but here is something that I learned in the past. Once I was just doing a quick run through on TurboTax to see what our refund would be. When I did that, I entered my DD's names, but did not enter their SS #s. I was very disappointed when I saw our refund amount compared to the year before.
Later when I was finishing up our taxes and entered in EVERYTHING, including the girls' SS#s, I was DELIGHTED to see our refund go up by $800! TurboTax would not give us the child credit until I entered DDs' SS #s!
Good Luck!