It never hurts to ask but don't waste your time and theirs unless your willing to pull the trigger!
The flip side is that if they come down substancially, they were trying to rip you off initially.
As a consumer, I only ask once for their best price on big ticket items and I make that clear. Don't play games with them and get it in writing!
Pricing is only relative to what the market can bare in a given territory. Getting a price on what someone paid 2000 miles away isn't always indicitive to what you might have to.
Steve