A bit harsh isn't it? Someone who does not let you in their home is someone you should not buy from and buying from a reputable breeder is what should be done like if not letting someone in your home makes you less reputable?
I am a NRA member I have a carrying permit as well and I am a great shot

, yet my home is still my home, I do not invite STRANGERS into my home business wise or other wise.
To the OP
The best thing to do when meeting locally is to meet in a public place for the buyer's safety and the seller's safety.
Now as far as question based on the answers you will quickly know if the person is a hobbyist breeder or just someone who had a pet that he no longer wants.
In the second case you need to ask yourself do you want what might turn into a possible rescue, are you up for the challenge it it is the case.
When purchasing the animal make sure you bring along someone that can sex the snake for you immediately upon purchase so you do not get disappointed down the road.