Unfortunately I've learned that comics do not qualify for media mail despite eBay allowing it.
Therefore, shipping costs have sadly had to go up and USPS has raised their prices.
1 comic (6 0z) $4.60 - all single issues are wrapped in cardboard for protection
2-4 comics (below 1 lb) $6.6
10 comics (1-2 lbs) $9
Once it gets above 2 lbs, the next best thing is a flat rate box for $15.75, but that can hold up to about 50 comics
So, my advice, if you're going to buy a few, I would really try to hit the 50 comic mark