All retail sales are up for negotiation in my opinion. What does it hurt to ask? Walk into both places and let them know you are planning on buying a bike and that both shops have it listed at the same price. One of the shops will make you a better deal to close the sale, or maybe they'll throw in those lights you want.
You could probably find the bike or something similar online for a better price, but there is definitely something to be said for buying locally. Since you are looking for a beginner's forum I'll go ahead and assume you probably won't be able to work on your own bike when it needs repairs, and this is when building rapport with a bike shop comes in handy.
I don't know about the specifics of the warranties you were offered but my instincts would tell me it's probably a ploy to squeeze a little more money out of you...but maybe I just like taking risks.