When purchasing used view cameras is it wiser to look to look at selections available at online sites(Badger graphics,KEH,etc.).Ebay normally has a fairly large selection also.What are the traps to watch out for?I'm considering stepping up from 4x5 to 5x7.I've used KEH for some medium format accessories and had no problems at all,but i've never purchased any large format equipment sight unseen from anyone.Any advice on this subject would be welcome......thanks..