Hello! That should definitely not be happening!
Which country are you in? Patreon automatically changes the currency to where you're at. ( At least as far as I am aware ) So maybe it's another currency?
I'm in Sweden and the 3USD tier costs " 35 SEK " here! Which is a little bit more due to VAT etc but ends up being < 4 US dollars.
25USD would be ridiculous though and should not be happening. I'm very glad you're trying to support so Patreon being weird is annoying cus I bet it happens to many people haha!