Pixelpiper
Super Freak
Do First Class shipping with tracking and it's under $3 for up to 8oz. If it costs $6-8 to produce how much are you thinking of selling them for? It's looking like a bare minimum of $15 shipped (with First Class) per set, some savings on multiple sets, Priority necessary after 1lb.
But the fact you're looking at requiring pre-payment for 250 sets looks like a deal-breaker to me. Unless you know a dozen other places you can also possibly take pre-orders. This is looking like a super niche product that doesn't have the necessary weight in terms of necessity or desire to meet even a small quantity run.
I'm not trying to rain on your parade, which is why I was trying to offer a more attractive solution that uses less material - I'm just being realistic.
But the fact you're looking at requiring pre-payment for 250 sets looks like a deal-breaker to me. Unless you know a dozen other places you can also possibly take pre-orders. This is looking like a super niche product that doesn't have the necessary weight in terms of necessity or desire to meet even a small quantity run.
I'm not trying to rain on your parade, which is why I was trying to offer a more attractive solution that uses less material - I'm just being realistic.