You won't get a heck of a lot for $100, even if you considered going used.
I'd spend about $300 to get a good pair. Then again if you are young and your feet might grow cheaper is better.
I'd go to a specialty place like
Tuxedo. They will fit you properly. Especially if you are like me and have really wide feet.
In any case I'd try and avoid the Sportchek type places. Then again if you only use them for an hour or two at a time, a few times a year you might not care if they are of great quality, fit, comfort etc.