If you have a friend in NJ then have it shipped there. Take a drive to a Apple store in New Hampshire, no sales tax in that state - perhaps not an option unless you have a secondary reason to go there. I live in NJ and love to hike and camp there.
Also, if the MBP you want to buy happens to be a 13" base model then there is hope. MicroCenter.com has an ongoing special for only $999, a $200 savings. The catch is that the special price is for 'pickup only'. The Microcenter.com store in northern NJ has an additional perk, 50% off sales tax, or only 3.5% tax. So a 13" MBP goes for only $1,034 with tax. I bought one there last June (then sold it for more than I paid six months later on ebay with some software loaded). This lower tax rate, 3.5% applies to all purchases so if you are looking for a higher end MBP, or anything else in the large store, the tax rate would still be only 3.5% and that store, Paterson, NJ, is relatively close to Tarrytown and right off the highway. They even let you reserve online so you just take your reservation to the pickup window - they do not bill your CC until you pick it up.
Some day in soon congress will mandate sale tax, at the time of purchase, for internet sales. Right now sales tax must be included if the seller has a presence in the state the item is shipped to.