I haven't found any $1 block accounts, but NewsDemon does have 10 GB for $2. It's currently listed right on their front page. Or just follow the link below & scroll down to "Non-Expiring Block Plans". How do I know this? I had exactly $2 left in my PayPal account, so I went looking around and bought this block yesterday
The money would have went to BlockNews (adding to my existing block) if only I had another 75 cents
Thundernews.com lists a 10 GB block for $1.99 (but no SSL, the same block with SSL is $3.99).
Usenet-News.net also shows a $2 block, but it is only 2 GB & PayPal is not an option.
I have no experience with either of these two...