Final results of the premium content poll were:
$10 a month - 5% (1 vote)
$8.50 a month - 5% (1 vote)
$5 per month - 20% (4 votes)
$3 per month - 45% (9 votes)
$2 per month - 0% (0 votes)
$1 per month - 5% (1 vote)
If you know me well, you'll have predicted that, to set the price according to what I feel is right in my Yeoli heart, I was simply going to average the votes. Doing so generates $3.90/month, which I'd just round up to $4. Which kind of makes me feel like an idiot for not offering $4 as an option on the poll. Well, whatever; a numerical poll allows for averaging and hence a precise value anyway.
Thanks to everyone for voting and even more thanks to those who commented, especially the long and intelligent comments full of numbers. I'll be setting up the premium system shortly.