I always use genuine printer consumables, as my experience through work is that recycled cartridges can result in more maintenance for the printer.
I was pleasantly surprised to see that the cheapest available genuine toners were from Amazon directly (rather than a marketplace seller). All four colours were apparently in stock (albeit two of them listed as "may require an additional two days for delivery") so I placed my order on 5th December, and they were dispatched on 10th December.
According to the Home Delivery Network tracking website my package was in Reading depot at 05:25 on 12th December yet they failed to deliver it until 19th. That's right - a full 14 days to receive my order. Even though HDNL had not even tried to deliver the package, I entered a new date on their website for a 'redelivery' and miraculously it arrived. I wonder how long it would have waited at their depot if I hadn't taken action? Amazon's reason was "adverse weather condition and the exceptionally high volume of parcels in your local depot". I'm only 10 miles from Reading and the conditions there were absolutely fine.
Obviously, Home Delivery Network aren't up to the job of handling volume at Christmas and are giving Amazon a bad name. Even more worrying, Amazon Customer Services seemed quite unfazed by it all and simply offered me a refund if I wanted to cancel the order.
What a crap experience.