I think it's a nice idea and I'm really interested to see how you execute on it.
I mentioned it on the form but I'll say it again here. I think for prices around what you're talking about it makes sense to make them per month $25/year is about $2/month, if you ask me to spend $25 up front for something I might think about it but $2 just seems like nothing.
Suggestion for the OP: offer a no-questions-asked money-back refund (say 30 days), and/or allow people to have a free trial period.
Optimizing a successful business around people who think $25 is a lot of money to spend at one time is a tough road (I'm happy to talk offline about personal experiences here). No offense to @almost, I'm not saying he's being cheap, only that he may not value this niche as other people (similarly, I would be a horrible customer for Pokemon anything). The bottom line is $25/year is about what paper refills cost for cheap day planners; not a lot of money in any objective sense.
I'd try to capture people who perceive more than $2/month of value in what you offer, and tune the product to offer them even more.
I mentioned it on the form but I'll say it again here. I think for prices around what you're talking about it makes sense to make them per month $25/year is about $2/month, if you ask me to spend $25 up front for something I might think about it but $2 just seems like nothing.