We can't express an opinion about a postage cost if you don't tell us what it was.
All we can do is to remind you that p&p (postage and packing) charge covers much more than the actual cost of posting. It also includes the cost of time and materials to pack items, postal insurance where applicable and eBay and Paypal's combined fees of about 15% on the total.
Allow for all of these, and if the p&p charged is still significantly higher it may be overpriced.
The p&p charge is shown in the listing, so you can usually judge whether it's reasonable before bidding.
