Which microphone is a better buy. Are any 30$ microphones ok for singing?

I want to buy a wireless microphone but obviously a $30 mic will not be of good quality and will break very easily. I have the choice of these two microphones, the "NAXA VHF/FM 110-270MHz Wireless Microphone System NX984", link http://www.overstock.com/Electronics/Naxa-Dual-Wireless-Microphone-System-NX984/3053813/product.html and second microphone is called "PYLE PRO PDWM100 Handheld Wired/Wireless Microphone" and the link is http://www.thedeepdiscount.com/p-901-new-pyle-pro-pdwm100-dj-pa-wiredwireless-handheld-microphone-system.aspx . Probably both of these mic's are bad, but please can you tell me which one is the better buy.