I will go against the grain here and say yes, I haggled with everything in my property, sometimes getting a discount, sometimes getting an free item.
best time to hit them is near the end of the month, where unit/cash sales are needed to make the like for like sales targets.
example: oak furniture land, dropped £4k on stuff for the whole house, haggled to include a free set of drawers and bed side cabinet to complete one of the bedrooms, total retail value of £400, so 10%
example 2: Victoria Plumb, done my two bathrooms with their gear, managed to haggle an undersink cabinet and mirror cabintet and various bits and bobs (toilet roll holders etc.)
those who say you cant haggle, just have never tried or been hard enough during the conversation, but it needs prep,
play one store off against the other, with price lists/total costs/any offers given.
good luck