I am a college instructor. I would like to use a wireless microphone to talk through the sound card and speakers on the computer in front of me (to amplify my voice). I have a low budget. Which unit do you suggest?
To connect a microphone to a computer, see the following link: Microphone connected to a computer sound card
A final thought: The level of amplification available from computer loudspeakers will be negligible. To understand more about voice amplification, please read: Audio Systems Guide for Meeting Facilities
For small portable PA systems, see: Anchor Audio