i know this may sound silly, but worth a try. when my now son in law needed several suits for a cruise, and had none, being a kid just out of high school, we went to the thrift shop of a hospital in a very ritzy area. we had to drive about 20 minutes out of our way to get there, but i'm talking top name business suits in superb condition. and each was only about 10-25 dollars. CEOs don't wear the same suit often, but take the deduction for donating the $600 suit to the hospital. we had lots of selection and top quality. consider finding yourself a thrift shop in an upscale area, you may be surprised. cheaper than renting and it's yours to use for your 15 year anniversary

btw- you are in for the experience of a lifetime. savor every minute of it. the food and the atmosphere are both spectacular. splurge for the wine pairings if you can, they sooo add to the meal. but be warned, each is a full pour. DON'T DRINK THE WHOLE THING, i have accidentally left there unable to find my way home- and we were staying at the Grand Floridian! maybe share with your wife, unless you have more practice at it than I.