+1 on haggling but acting superior is a little misleading, indifferent to buying or doing buisness is perhaps a bit more accurate. Don't show direct interest in the object that catches your eye, don't point it out to whoever your with. Look generally at the wares being offered and get an idea over the type of starting prices the vendor is using by inquiring about items that you have no real interest in, this will help you keep emotion in check and get a feel for the seller. Be prepared to leave and check other sellers wares doing the same thing with them. When you've found something that you like , return to that vendor, ask them for a price remaining indifferent, whatever price they give offer them just over half. They will act offended and give you another number, split the difference and they will likely counter again. Leave, but don't rush out they will most likely offer another number, decide to buy or not. If they don't offer another number keep going and come back later and offer a little less than their final price most likely they'll accept. This will also work at flea markets and buying a used car here in the US.
Look at the quality of the carving and finish also look at the case. Carry some pipe cleaners to check the alignment of the drilling. Be critical in your assessment and use any niggling flaw you can find to drive down price, and if it happens to be perfect don't show excitement or outward pleasure until after the deal is done.
Bearing the burden of responsibility..... It's probably my fault.
Treat your silver as if it were earthenware and your earthenware as if it were silver - Seneca, Letters of a Stoic