I have noticed on EBAY some Marklin items have ridiculous shipping costs when buying. Here is one example: "Assorted tires $6.84 + $55.24 shipping". The shipping cost doesn't make sense for an item that can be sent in a letter size envelop, yet someone posted a review after buying the item and was happy with the purchase and commenting on the shipping cost as being so high. The item was posted in Great Brittan.

eBay now tries to get sellers to provide the postage costs at the time of listing, so many sellers just use the same information for all of their listings (parcel size). I recently went through a problem where I had to go through hoops in order to list an item based in Canada on eBay.com and the site wanted USPS shipping, which I cannot offer from Canada. I could not leave the shipping to the end of the auction and let the buyer pick from available options. I had to list one item as "local pick up only" and list shipping options in the description and for the second one, I ended up putting that on eBay.ca and still had to pick a rate from Canada Post. I normally offer buyers basic shipping plus an option if they want expedited or more packaging (protection) which costs more.
I then found out that eBay charges a % of shipping costs as part of their fees. I ended up having to eat 10% of the shipping costs out of my end.
Since then I discovered that you can buy your shipping through eBay (at the time of the auction it was Shippo). You take advantage of their shipping volume discount and then give some of it back to eBay in form of the fees. I don't know if this comes out cheaper than my own rates, but it is definitely scam-like.

I have ordered some items (HO Scale container, close couplers, pantographs) and had the seller list the price for a large shipment.
After clicking on "Buy It Now" or winning the auction, I simply chose "contact the seller" and asked them to provide an invoice with small packet as shipping option or asked them to send it as lettermail. Most often, they are willing to do this. I have had two auctions where we agreed to call it off because we could not agree on the shipping rate. One on eBay and another on another site. Neither ended up as a black mark on my account.

Regards

Mike C