Dude that would be awesome, i'll cover the shipping cost and time as well. I think I saw an add in the paper for a mario costume, with a seemingly well done hat, is it really the same?
I wouldn't know, there's a few costumes floating around.
There's a generic type thats labled as "Plumber" and has some of the worst looking overalls i've ever seen, and comes with a red T-SHIRT, mustache and hat (no "M"), but the gloves are sold seperately.
Then there's one from Nintendo that actually a Super Mario Bros costume, official stuff, but the picture on the packaging still didn't look too great (though I didn't get that good a look since i wasnt interested at the time). There's also an officially licensed Yoshi costume from Nintendo, but it didn't look anywhere as good as the last Yoshi costume I posted:

Lastly, the Mario hat I'm speaking of was its own seperate peice. Its officially licensed merchandise but there was no costume with it, just a hat. This leads me to believe that Nintendo being the money gaugers they are, sell the Mario costume seperate from the polyester Mario hat. It looks decent, just a little too big to look proportionate on a human head. I'm pretty sure its the same one that was shipped out to Elite club nintendo members.