what to get my bf for our third anniversary

hello all, i (20F) need advice on what to get my boyf (20M) for our third anniversary of dating. we usually celebrate valentines and our anniversary together since they are only a week apart.

he loves minecraft and building housings on hypixel, he also enjoys star wars and horror movies. he cosplays as michael myers in full screen accurate gear, so he takes his craft pretty seriously. he’s double majoring in chem and bio but LOVES organic chemistry. he also likes indie music like lord huron and bastille.

he is very sentimental and loved to create custom gifts for me. for example, on our first anniversary he had custom minecraft figures made of our skins to symbolize our first “date”. in the past, i got him custom legos of us with our anniversary printed on it and an etsy print of some biological stuff. i’m just not sure how to go about this year’s gift. i know that the third anniversary is glass or leather. he already has a nice leather wallet and belt, so i’m leaning more towards glass. i thought maybe a glass periodic table or something chemistry related but im not sure

my budget is $200