[BWStearns]

I would say if they're a large company you can, since you're wasting a pathetically small amount of their cycles. If they're a small startup I would say that it is less conscionable as the impact of taking time to talk to you is significantly higher. The leverage bit can't hurt, after all they want to have leverage over you; at core it's a business arrangement and no one should have their feelings hurt over treating it as such.