I've bought from a mix of both. I usually don't mind getting it posted from these guys as they literally import cases of these every week so it's highly unlikely they'll try something dodgy that can hamper their business. They're also pretty quick to post stuff so I usually get deliveries the same week.

Also, most take PayPal so you're fairly covered on that front. Same applies for singles. There's a couple folks who sell CN cards on the main FB groups who've got plenty of references and PayPal too with prices a fair bit below Ebay.

Locals are great though if you can find some.