@Auds424: I don’t think everyone should go around assuming that your boys can’t afford or don’t have any reason to wear tuxedos. Like Pixie015 said, it’s the only major apparel purchase for the wedding that has any shot in hell of being used later in life. If they have reason to own one (say, for example, they are professionals who attend black tie events or fundraisers) it’s not a terrible thing to look into. At my old job, I had one black tie event per year. Sometimes two. So I bought one. Doing so saved me money.
The only thing I’d suggest is that you give them a little wiggle-room on what sort of tux they have to get. Not everything works for everyone, and owning a tux that you hate might be unbearable. If you made me buy a 3 button, notch lapel tuxedo, I’d throw a fit in the store because I’d never wear it again—good look for some, but just not me.
Renting v. Buying: You can find decent tux rentals. The wool should be more like Super 120s instead of the Super 100s or worse—a wool blend. My place was great and did an excellent job of hemming the pants and sleeves so that they were hitting everyone at the right place. So when you rent, tell the store, “Now I know that the tuxes come with extra length on the sleeves so that they fit more men. Will you be able to hem them on the day of pick-up?” Seriously, it helped the rentals look much better. Nothing they can do about the boxiness. Just get flat front pants and the most expensive classic tux they offer and hem the legs and sleeves.
Also, rental bowties can be rough. The place I went to offered bow ties that were hand-tied around the fella’s neck by the staff and then unbottoned in the back. So you didn’t have to learn how to tie one. They tied it the day before and you simply snapped it on the next day while getting ready. You had to buy the tie, but you looked better than the other tux people with the clip ons 🙂
I bought mine for my wedding. I saw one from a designer I liked at a store at about 2/3 off the regular price. The alterations cost about $150. (Take in the sides, alter the sleeves, shorten the length of the jaket, hem the pants). When you don’t rent, you need to also budget for the cost of the shirt, tie, studs, waist covering, cufflinks, and the shoes. You can stalk online retailers for big sales if you have enough time. And shoes: you can wear plain black shined shoes if you already have them. Or make it a good time to invest in a new pair of black dress shoes. I chose to get patent leather and just stalked Endless.com.
Anyway, those are the considerations when you ask someone to buy a tux. They may find a great tux on sale for $250. But there’s still going to be all those other things they will need to buy to complete it. And the alterations. It’s all very hard to do for under $500.