UPS with brown tamper tape, don't even declare value, just send it and it'll get there, make an arrangement with buyer and escrow to split btc if it's lost, tracking will show if something happens. I've had 10btc Cas shipped to me no prob. High declarations/insurance draws the most attention. Otherwise Fedex overnight. Wait til spring/summer, snow can mess up deliveries. There's always a chance, but it's pretty rare.