Well Mrs M, I'm based in the UK and most ebay sellers quote sky high postage costs because they assume we all want our goods tomorrow!
I have discovered the clipper route round Cape Horn! (Well it seems like that) On the whole surface mail takes 4-5 weeks from the US and about 6 weeks from Australia. To save money, I'll wait!
In terms of costs I always try and get US sellers split things up so they are under 4lbs and then they can go letter rate - most of my imports from the States cost between $6 - $11 which is almost as cheap as domestic - its just that the US sellers don't know the USPS surface letter rates.
Most other countries have similar bargains. The trick here is to always download the national rates (usually pdf format) off their Postal services web site. Check the country code, many sellers get that wrong and pay higher than necessary postage. Most importantly check the "break points" The other day I bought three cameras and told the seller just to ship the one I was interested in - he was obviously delighted!
At other times I've told them to ship it in two parcels - most do if yoou ask nicely and say you'll pay packing costs.
A bargains not a bargain if the postage costs more than the item!