If you have low pile carpet such as a basement, or an astroturf'ed patio you can't get a better vacuum for that. $30 is a bit high for me for a 40 something year old vacuum, but if it runs good and considering it has the full attachment kit(those sell for $15-20 on eBay) it just might be worth the $30.
I found one just like that in the trash in 2010 but got rid of it, was before I was a collector.