postage charges vary from seller to seller so if you have your eye on an itewm always check out other listings and see what the average postage cost is.
if you know aproximetly how heavy it is and you know what service it is coming by why don't you check there website and check rthe prices most of th time its royal mail so:
you could then email the seller and try to negotiate the postage prices and if its over the top and the seller won't change the postage just forget about it.
some say well its ok to charge extra for things like a 'handling charge' marker pens, paper etc... but why - there choosing to sell there item so they shouldn't make others pay for things they should have as a seller.(see above)
Also as a buyer when you put a bid in you are entering a legal contract - which means you have to do what it says. if in the postage it says see description/listing ALWAYS contact the seller before you put the bid in as they may charge you as much as they like and as you are in a legal contract you have to pay or you will have your ebay account suspended etc...
finally if you see an item worth £200 and it is £0.99 with £199 p+p report the seller to ebay as they are breking ebay rules and are evading costs. why should some pay for costs and not others. ebay wouldn't exist if no-one payed the full fees.
in conclusion keep your eyes open for bargains but beware it may not be what it seems.