Can anyone comment on the situation regarding the drop in bitcoin price recently and knock on effect for vendors , I can only think that they are not getting the price they desire , they must be making a loss or am I wrong ? I would like the view of dom vendors and those in the know.
For vendors using escrow, a $ per BTC price drop will cause them to lose money, yes. Those vendors that offer FE products are not necessarily as affected, though if they're hoarding bitcoin and the price drops before they cash out then yes it is a loss as well. There are hedging opportunities available to lock in specific $ per BTC returns, though I'm not familiar with them. Trading in the BTC futures market is a possibility. A vendor also can just cash out as soon as possible to mitigate the damage or choose to hold onto the coins until the price rises again.
If you're referring to the prices they charge on the markets, these are typically set in USD and the bitcoin cost of the product(s) adjusts accordingly. It would be very tedious if vendors had to constantly update their product's bitcoin price.