I have a couple of the store branded Personna blade packs with the dispensers, and they have a bank built in to them.
I use a feather plastic blade box. Threw my first one away yesterday, nearly full after almost 5 months of DE shaving.
I do the same thing. You can get a lot more into the Personna blade packs than came out of them. Similarly I save the empty blade boxes and pack them full of old blades. My city does 100% recycling so they just go in the trash.I put them in the slot on the back of the plastic blade box (Feathers). When I finish with the five pack of blades, I put them in the recycle bin. Our local pickup accepts mixed recyclables. Metal, plastic and paper all go in the same bin so its not an issue to put metal in the plastic box.