Like people have already said, its not too big of a deal. The eyes are a very small part of the cosplay, and no one will be confused as to who you are without them.
As for the ears, you can just keep your hair over your normal ears and no one will notice.
There's also this site: http://www.aradanicostumes.com/elf_ears
There are a few reviews of aradanicostumes on this site, and all of them are pretty good. (At least the reviews of the ears are.)
It has a bunch of really good, cheap ears (like, $12 or so) and I'm actually going to order from them for an elf cosplay I'm planning. Just don't forget to buy the Spirit Gum!
Hope that helps!
2013 Conventions: LouisiANIME, A-Kon, Mechacon
Sansa Stark (Game of Thrones)
Amon (Legend of Korra)