YuGiOh cards come in all price ranges and conditions.  Any semi-intelligent buyer can tell what is a good deal and what is out of the price range.  This guide is a quick "what-to-look-for" guide for shipping costs.  Some sellers sucker you in with low initial shipping costs such as 1.00.  Although this may be a good deal, you have to answer several questions first:

1. How will the item be shipped?

If you want to receive you card in good condition I suggest avoiding the 1.00 shipping sellers unless they have an abnormally large feedback rating. Most people would rather pay a little extra for the extra protection of double sleeving and bubble mailers, etc.

2. What kind of protection will my cards receive?

If this info isnt in the auction you should always ASK! If you dont ask before buying then you have no room to complain once the item arrives.

3. How long does it take to get my cards once I have paid?

For this information you can check feedback reviews and also check the average time between sale and feedback left by buyer to guesstimate shipping times. Some kind of Delivery confirmation is also a HUGE plus!

4. What kind of combined shipping rates does this seller offer?

This is the biggest thing to look for when buying often on Ebay.  Some sellers allow up to 10-20 days to buy all you can to save more on shipping costs.  For example, if your buying 5 cards and one seller has them all you can be suckered in by the lower initial rates but come out sour in the long run.  Seller A and B have the same 5 cards at the same price.  Seller A offers 2.50 shipping for first item purchased, and then .25 per additional item.  Seller A shipping costs for 5 cards are 3.50 total.  Seller B offers the 1.00 shipping rate to draw you into their store or listings, but rarely offer any shipping discount ofr multiple purchases..  5 cards at 1.00 each is 5.00 shipping and will usually take longer to arrive and not be handled as carefully pre-shipping.

Well, hope this helps.