Need help on where to buy scalpel replacements

Just ordered an orange Roxon C mini as i’m making the switch from my victorinox. I’m in NYC and carrying a knife gets annoying as i’m a college student and don’t want to get my balls busted. I ordered the scalpel implement to replace the knife so I can just ditch the blade whenever I want but after doing some digging trying to find replacement blades it’s a little confusing on what to purchase. Does anyone have any cheap recommendations?

Thanks in advance