When I use 2 livesteam alot an I had to use like this sad dollar store mic for a bit I use 2 tie a shirt around my mouth like a bandit . I sounded good an look pretty good doing it haha, if you cover yourself with a heavy blanket (yes, you'll look like an idiot) it will block out a lot of the external sounds and sound really good.
yeah right 100$ !!! The cheapest Blue Snowball just costs 65$, if i had 100$ I would buy that one to save my 35$!!The Audacity tip is a great one. Make sure you can cut out as much external noise as possible and talk clearly.
Put a little money aside every once in a while and buy a decent mic for around $100 USD. My recommendation is the Audio-Technica AT2020. Cheap and very good!