I also happen to be one of the worst negotiaters in the world.. I would love to pick up one of these pianos - but I feel like I am at a used car delaershipp dealing with these people... They were trying to force me into leaving a deposit yesterday..
Don't let them intimidate you. You worked hard for your money I'm sure. Some sales people are like sharks or wolves, they will sense hesitation or weakenss and close in for the kill.
These days, unless something is a spectacular deal, pianos are not exactly flying off the showroom floors. I have been piano shopping for a couple of weeks now and I can't tell you how many times I was told that unless I left a deposit the piano would probably be gone when I returned. Perhaps, but the odds are in my favor. Every one of the pianos I first looked at are still sitting on the showroom floors. You may have to walk out and see if you get a phone call the next day.
This is an important decision. You may want to consider zeroing in on which one of the 3 you like the best and then concentate on negotiating that deal. What you like is most important. Which one "sings" to you? Zero in on that one. Trying to negotiate 3 different pianos is going to make you crazy. Of course, if you can't get a fair deal then you may have to pursue another course so it's always good to have a plan B.