well i understand they won't all fit in a small flat rate box because i know how big those are but if your shipping them media mail and wrapping them in the brown paper its not going to cost $10.00 or more to ship 4 books no matter how big they are.i have shipped 20-30 comic books in medium sized clasp envelope and only cost me $3.00 and 75 cents for delivery confirmation. people thats been on here awhile knows this as i do and we would like to have the books but not willing to pay a fortune for shipping cost. you would get more bids and probably even gin if you set a exact price on shipping cost.
I just got 5 books using media mail was $6 they go by weight did u weigh the books in a scale and check USPS site fir media mail please it's tight right now
you could ship flat rate cheaper. they have envelopes and they are like $5.35 to ship and then they have other boxes as well. not sure there prices on those but would be a lot cheaper than weighing and doing zip codes. just a idea!