For personal travel we have done it ourselves very successfully, specially lately (in the last 6 months or so). That is, wait until the last moment to book lower fares. I guess it is the economy and the airlines trying to attract travelers even at rock-bottom prices instead of going banckrupt.
But, being seasoned travelers we do understand that we are running the risk of not finding the "deal" and having to pay the premium.
I guess as far as your guests understand the risk and the consequences and are willing to pay for them instead of just not showing up at your wedding then it is OK.
However, welcome to the forum and wish you the best!