I really don't want to critisize OP since building stuff for yourself is always a good mentality. But lets be realistic, 1000$ over 10 years is nothing. It will always cost more if you consider your own time for maintenance long term. Obsidian is one of the most consumer friendly business for note taking out of there, they are not VC so the Evernote comparison is unwarranted IMO.
Where is the limit ?
While $100/year maybe doesn't sound like much, it's hardly the only subscription service you have, and they all add up, from your mail provider, office suite, cloud storage, streaming services, phone bills, internet service, etc.
Personally I find $100/year to edit notes on my phone to be a bit much, but then again, I just use iOS Notes.
I am so fed up with everything turning into subscriptions, that I've just completely stopped buying things that are subscription based.
I understand developers need to make a living, but simply throwing a subscription on top of it won't convince me to buy your product. You convince me by making a compelling product, and by continuously updating it, adding new features, which will convince me to buy another version.