1.)It depends on the seller. You got to check if they have box sets. I know they have naruto box sets but only from 1-27 and it cost $300. They ven have deathnote box set, it's not fair.Hm, I might think of buying it from amazon but I never used it before so I got a few questions...
1.) I've just went on amazon to check and they only sell it piece by piece not like "One Piece manga 1-5x for w/e price"?
2.) How do you know which sellers are trusted and which ones sell at really really good condition?
3.) Can you buy the books using a debit card or something?
Sorry if these question(s), sound slightly stupid xd
2)You just check the rating of the seller. Make sure you they have 4 stars or 5 stars. That's what I do. Amazon is more trustworthy that ebay xd.
3)Yeah you can use a debt card.
Shipping will be really high since you are going to buy each volume separately.