You'll have to search those sellers out yourself because just entering that description I found over 3 million items!
Those sellers will not come to these boards to seek their buyers, you have to seek them out!
Down the left sidebar if you have a particular theme, you can select that, and it'll narrow the search down a little.
If the seller is using GSP, they will not be able to combine shipping.
Also never take it for granted that others who don't offer GSP , automatically offer combined shipping, a lot of sellers don't, preferring to have individual tracking numbers for proof of delivery.
If buying more than one comic, ask before buying and paying , if the seller does combine shipping.
@domorowski1963
