YOU contracted with the company right? YOU signed the contract right? So what if the box isn't opened... if I sign a lease for a car today, take it home and then never drive it out of my garage, am I still liable for the term of the lease? You didn't mention if they waived/included statement fees, batch fees, set-up fees, etc., and if they did this doesn't sound like a bad deal. Actually it doesn't sound bad anyway since I've read many posts where terminals are much more expensive... and you didn't say whether the terminal dials through internet for phone, wireless, etcs and that makes a difference too I suppose in whether there's value to a internet terminal that doesn't require a $50/mo dedicated business phone line. And how about the replacement warrantee if it breaks down? Or the pre-tax benefit you get for leasing?
Whatever the case, you had a meeting of the minds or you wouldn't have agreed to sign the contract and if you're just now having second thoughts, that's sort of on you isn't it?