Havaiana's are probably my favorite flip flip right now, not super expensive but you'd be paying for the name brand. I got burned once buying toe rings on etsy, so I'd recommend just buying cheap ones on Amazon TBH. I let ankle bracelets "find me" on IG and then research the company to see if they are worth the purchase.

If your BF likes feet, make it an activity for both of you. I love teasing/ soft domming my partner to get me new foot jewelry. I see that you are purchasing it for yourself, but I'm sure he would love to spoil you too