You need to get over your fear of grade deflation. I do not agree with grade deflation for deflation’s sake, but I do think employers and grad school admissions committees become familiar with what a typical transcript looks like from various schools, especially from schools that produce as many graduates as Purdue. They will know about the grade deflation.
I doubt that Purdue is lacking in academic opportunity. Your own bad attitude (my parents are making me go here) and your lack of initiative (not wanting to risk trying a class that might be a weed-out) are holding you back, not your school.
Are you sure you’re willing to work a decade or two to save up money to go to a fancier undergraduate then graduate school in economics? By then, you may want to start a family (with someone you haven’t met yet) or you might just be tempted take a trip around the world with the money you saved up rather than give up the freedom of the working life to go back to a school schedule. (My spouse went back to school with a 4 year old and a 1 year old at home, it was not a typical college experience!) You probably cannot appreciate how different a person you will be in a decade, so just trust your elders on this one.
A decade or two is a very, very long time to put your true career dreams on hold. Especially when you are sitting at a good school with a full tuition scholarship right now.
Also, the value of a degree is based in part on the number of years you are able to sell it in the job marketplace. If you go to college in a decade or two, you will not have those working years ahead of you.