Personally, I wouldn't put a lot of faith in Black Friday deals; not on popular and well-reviewed TVs anyway. The reason is supply and demand.
TV is slim-margin stuff. No retailer can afford to chop the price of a TV by a hundred quid or more without losing money. That means any big price changes come from the manufacturers realigning prices. When a product is 'hot', which the KD-55XF9005 currently is, and there's a big price jump between it and its newer replacement (KD-55XG9505 - 2019), then if I were the UK Marketing Manager for Sony TV, would I want to sacrifice a load of margin and create a big product shortage just before Christmas?
There'll be a little bit of price movement to meet dealer and consumer expectations of what Black Friday is all about, but IMO, unless the price has hit £849 at some point in the 6 weeks before this years BF date, then I'd be very surprised if it got to £800 on the day.
The XF9005 range launched in April/May of 2018. It has already gone through one Black Friday (Nov 23rd, 2018).
Pricespy has a pretty good price tracker, so it's possible to see what happened with prices around that date.
About a month before Black Friday, the TV hit its lowest price of the year-to-date @ roughly £1050. Then the games started.
Four weeks or so before BF The price went up to £1150. This was so that they could show a big saving during the event. There were a couple of small price drops in the days before the event to get consumers to jump early. Then on the day the offer price was £989. That seems like a decent saving from £1150, but it's really only £60 less than the previous best of £1050.
Post-BF, the price spiked again to £1049 before dropping to £949 a couple of days before Christmas 2018 when both Sony and their dealers knew that it was too late for a pre-Xmas customer delivery unless the dealer had stock. The price dropped even further to under £900 just after New Year's Day.
Prices were consistently low @ £899 across June and July this year. This coincides with our main holiday season. Late sunsets mean that people are outdoors more (weather permitting), or abroad. Either way, they're spending money on other stuff rather than new tellies. There was a brief dip to £799 to coincide with promotions for the World Cup soccer in mid-July before returning to the £899-£949 range.
I see very similar patterns with other popular TVs. Black Friday is good if you're buying something either high-margin or gear that hasn't been that popular. For low-margin gear in high demand though, you're better off buying at slack times such as summer or in the lull around New Year.
@5punk3monk3y is correct about <£600 55" TVs being low end. There's still stuff cheaper of course. It doesn't take much work to find TVs at £350, and on paper they'll seem to offer similar features. What won't be so easy to spot from the product descriptions with be things such as the lack of brightness of the backlight, or how the video processing struggles with motion, or that maybe the 4K panel itself isn't up to the standard of the better brands.
