BuySpry via eBay offers the refurbished Unlocked Apple iPhone 7 Plus 256GB GSM Smartphone in Black for $384.78 with free shipping. That's the lowest price we could find for a refurb by $16.
Note: A 60-day BuySpry warranty applies. It ships with an MFi-certified cable and power adapter.
You very likely are putting your laptop battery into an early grave.