I just bought the mask for 10€.
Then I bought a unibody lycra red costume and some fabric paints.
I add some spare blue led so I did a cheap heart and a lighting mask.
The cost is about 40€
Step 1: Lighting the Mask
No switch just a magnet!
no batteries handler just cable straight soldered on them!
For a night it was enough if necessary I could improve it.
Step 2: Let's Paint the Unibody Costume!
As you can on the picture fake muscles look good ! it is my best ever 5 invested € :)
I am not skilled in painting and the iron man costume is quite complicated to do if you want to be accurate! I had just one week so I follow so main part of the official armor and then I improvised!
Step 3: Final Version
So Ok for some people I was spiderman :S lol but it was great fun to try doing it and you know what I used it for halloween as Iron Man Zombie.
So enjoy and try it :)
PS: Just one more thing, I FORGOT THAT THERE WASN'T ANY ZIP TO GO EASILY TO THE TOILET but anyway I managed :)