M$50-500 if I think it was worth looking at. M$10k for something if I use it once a week for the next two months. I don't need to never heard of it, but your recommendation needs to cause me to use the site when I wouldn't have otherwise. (ex: the AI search tools I currently use are exa.search and perplexity.ai and they're both good)
edit: Context, to give an idea of the way I use - I have several thousand lines of of handwritten shell and editor plugins/configs, as well as a dozen custom-built cli tools that I use weekly. I spend a lot of time reading papers/blogs/books on the internet, including semitechnical ones in areas I'm not specialized in, and wish there were better ways to find more of those. I read lobste.rs. But beyond that, I have a bunch of random interests you wouldn't expect that'd be too long to list here, and often get new ones.
Sorry if it's overkill (had to split into comment replies due to length), but here's everything from my bookmarks that others may find useful.
Mathematics
Kagi: web search engine with a subscription-based business model instead of an ad-based one, and also with some effort put into fighting against the sorts of SEO that Google is susceptible to, such that I've found its results to be pretty consistently better.
Marginalia Search: mini-search-engine optimized for finding things on small obscure interesting websites of the sort that more traditional search engines would deprioritize. Not great for finding whatever you're actually looking for; often can be pretty good for finding new obscure interesting internet-corners tangentially related to whatever you're looking for.
Trakt: tracking of what shows you watch and what new releases are upcoming. I mostly use it for its episode-calendar feature: given a list of shows I watch, it'll give me a list of new episodes coming out for those shows in the near-past and near-future, thus making it easy to remember to watch the episodes (where otherwise I tend to forget and/or to not realize they're coming out in the first place).
privacy.com is an absolute must-have service to keep in your toolbox. You can use it (for free, idk how they make money) to set up virtual credit/debit cards with a hard spending limit, which are backed by your actual credit/debit card. I use it when buying something from a place I don't necessarily trust completely (AliExpress, Alibaba, etc). But in my opinion its best use-case is for "free" trials that require a credit card. Just set up one of these with a spending limit of $0.01 and when your free trial expires it'll try to charge this card, but will decline. So you never have to worry about remembering to cancel your trial before it renews. Same thing with promotional deals where some service is like $5/month for 6 months but then $25/month afterwards.
OneLook Reverse Dictionary/Thesaurus is amazing for when you can't think of what the word for something is and it's just stuck on the tip of your tongue - type in a description of the word you're trying to think of and a whole list of words and terms comes up. Also useful if you're trying to think of a better way to refer to or describe something; also useful for finding new terms for things - honestly just a super useful tool in general
I'm into finding good background music/noise while I work. Not sure if you are too, but here's what I like:
mynoise.net Lots of good customizable background sounds (white noises, rain on roof, cafe, train, etc.) Why I work better when I'm playing the sounds of being on a train is beyond me...
radio.garden Listen to radio stations from all around the world. There's something cozy for me about being one of the (presumably few) listeners on an obscure station across the world late at night.
my70stv.com You can put on random TV channels from any year in any recent decade (the other sites are in the sidebar). Once again, just background noise for me. Like the radio stations, makes me feel cozy for some reason.
radiooooo.com basically the two sites above combined!
everynoise.com Discover (lots of) new genres of music. Sometimes I give my evenings a theme, like "finnish pop." It's pretty fun.
isthereanydeal for finding the lowest price on games
Dark Reader, the Chrome extension for adding night mode to sites that don't have it
Tabliss, Chrome extension to give a cycling cool picture in new tabs, kinda like a background
Page for if you lose your phone (for Android): https://www.google.com/android/find/?u=0
wikipedia's [year] in [topic] pages for topics you're interested in.
e.g. https://en.wikipedia.org/wiki/2024_in_sports
https://en.wikipedia.org/wiki/2024_in_film
https://en.wikipedia.org/wiki/2024_in_video_games
every page has lots of subpages for subcategories of those topics
If you know nothing about a particular subculture it can be one way to get a particular kind of overview of what's coming up in it that matters
GrayJay for android, currently still under construction but it seems stable.
It's like a front end and adblocker for Youtube but not just Youtube and not just for adblocking. It has plugins for whichever site you want to get feeds or content from. Youtube is one, but also Twitch, Patreon, Rumble, Soundcloud, and others. Then you can have all your feeds showing up in one place. They bring the dislike button back. It's super customisable.
Roam is a personal wiki tool that has benefitted me a lot. I used to use Google Docs or txt files for my notes instead. https://roamresearch.com/
I'm sure competitors like Obsidian are also pretty good.
The Rave app (https://rave.io/) is easily the best watch-party app in my opinion. It has all of the different platforms you could want in it as well as just streaming straight from the web. It's really good for long distance relationships, or even just chilling with some friends.