Depends on the shop and the attitude of the sales rep. Rude and unfriendly sales people will generally get low ball offers from me mostly because I know they will turn down the offer, thus giving me the perfect excuse to just leave and not come back.

If they're friendly and not too pushy, I'm a little more supporting and will only hagel on the price to a certain degree that will not insult them in any way, cause I want to come back and do more business with people who give a shyt about providing good customer service.

Most of the time, I will just end up paying cash on discounted items, even if its just a little discount, anything is better than nothing. all regular priced items are always paid with my rewards card.