Honestly I'd go raid your nearest Dollar Tree for inspiration. I'm always surprised at the cool stuff they have there (as opposed to Dollar General and the like which, at least where I live, can be kind of junk-y). There's the 52-reasons-I-love-you card book that everyone makes if you end up not being able to think of anything else. If you know how to knit/crochet you could just buy some yarn under $5 and make him a hat/scarf/yarn mustache or something like that. If you don't know how, it could be fun to learn and you can do it for free here
! You could also hit up a thrift store (or even the dollar store) and get a cheap frame and then make a collage with pictures from your relationship and put it in the frame. Orrr since you mentioned that you like baking (but if you're anything like me then your boyfriend has been taste-testing your creations forever) you can make something special that you've never made before. I think petits fours are cute but I know they're not the manliest thing ever. You can make any baked good look special just by decorating it more elaborately than you normally would.
Sorry for how ramble-y and incoherent this has gotten. Good luck with your gift hunting!