The short answer is yes, a bid on eBay is considered a contract
to buy, but that isn't a hard and fast rule. If the shipping is out of the norm you can report the seller to eBay and explain why you want to withdraw the bid and they may cancel it for you. One of their policies
is that the shipping has to be proportional to the product. High shipping fees are one of the ways the sellers used to scam buyers.
Also, if the items are listed in such a way as to lead you to believe they are real but are fakes, then there is potentially fraud involved and there wasn't a contract formed anyway because there was no "meeting of the minds". Again, the best thing to do is notify eBay.
Realistically, they won't go after you for this type of transaction so you're safe.
Thank you for allowing me to assist you. I believe I have answered all of the questions you asked so I would request that you please click the ACCEPT button so I receive credit for my work and leave feedback if you have a chance. Please consider clicking "BONUS" as a nice way of saying "thanks" for a job well done, although this is neither required nor expected. Please remember that we can only base our answers on the information you provide and sometimes a misunderstanding as to what you are looking for or already know occurs so feel free to ask additional questions. Please be aware that my answer is not legal advice, it is merely information and no attorney client relationship has been formed. You should always contact a local attorney for legal advice.
Several customers have asked how they direct a question to me in particular. If you specifically want me to provide information for you just put “FOR TEXAS ATTY” in the subject line and I will pick up the next time I am online.