Google, goodreads, agree https://www.goodreads.com/quotes/581461-aspire-to-inspire-before-you-expire Eugene Bell Jr. > Quotes > Quotable Quote “Aspire to Inspire before you Expire!”

It is not common or familiar. I've never heard it before. On checking, I would call it a quotation rather than a saying; it's specially associate with one person. Thomas Edison supposedly said "Genius is 1% inspiration and 99% perspiration" (that is, it is mostly hard work, not brilliant thought).

Not heard it. That in itself is not indicative. The Pronoun "I" is a little strange with the imperative. . Would maybe expect Aspire to inspire until you expire. But the true forms of sayings are often a little strange.