You only pay taxes in the state of purchase if YOU take delivery of it yourself. Have them take it to the state line and pick it up from there.
Ask Vagrant about all this. I'm going to get his boat this weekend for him BUT if I pick it up at the dealer he has to pay Ohio taxes so I will be picking it up in PA. Makes no sense that if he hires someone to get it why he still has to pay the Ohio tax.
The same happened to me also when I bought my boat. Had them deliver it to me NO TAXES !!!!