As have said before, with pearls you get what you pay for. Unfortunately if someone offered a diamond for ?5 people would probably not believe it (although depending on the size etc they might be wrong to discount - diamonds aren't actually very expensive, just very well marketed) BUT with pearls you do get what you pay for has always been my experience of buying quite a few over the last 101/2 years and being around other buyers as well)
It's a bit like estate agents (trans realtors) say, a street has a price for the properties. They may vary and you can negotiate and get a deal because a house might be a bit run down or the seller need to sell quickly or they could hold out for a full price..but the price is at a certain level, plus or minus a bit.
Same with pearls.