On his Smilers-Info website, Graham Howard writes about all new Royal Mail Generic Smilers sheets, and also about all the Business Customised Sheets generated mostly by major first day & commemorative cover producers, and the 'jump-on-the-bandwagon' Commemorative Sheets produced by Royal Mail for over 3x face value.
I've predicted that this bubble would burst, that with the ever increasing number of 'posters' containing stamps churned out at prices from £25-£50 each collectors would say "enough is enough" and that's the way things seem to be going. Many Royal Mail sheets can be bought on eBay for less than original selling price - sometimes for less than (current) face value. And while certain popular short-supply sheets have always been expensive and always will be, many Business Customised Sheets produced to cash in on the collector whim are now on the market at less than the original selling price.
As Graham writes in his latest update:
There was a time, not so long ago, when we looked forward to receiving the next 10-15 business sheets that had already been announced. Not so now! As the deficit bites so our disposable spending reduces and I think this may in part be impacting the choices that collectors are making. Not only are there less sheets these days (not a bad thing) but they are announced days, not weeks, before their appearance. I think all sheet producers, including us, are taking a more cautious approach with future issues, Ridgewood for one has decided that fewer more significant sheets are the future - we will leave the trains, boats and planes to the other producers.
Business Customised Sheets were originally intended by Royal Mail to be created for businesses to customise their mail. They even promoted the use of customised coils, though none have ever been produced as far as we know. The first were produced for Eagle Coaches of Bristol in small numbers and under 10 are thought to be in collectors' hands. The next batch appeared for major football clubs, and the England Rugby squad, and soon stamp dealers realised that they could make money by producing 'collectibles' with images of Elvis, steam locomotives, Dr Who, and royalty - in which the stamp element was purely incidental. Some were produced with different perforations or by different printers, which was why they were initially of interest to collectors. But they were never going to be listed in stamp catalogues.
The stamp dealers, in conjunction with Royal Mail, were producing - in effect - glossy colourful posters, which happened to have 10 or 20 1st class stamps in them. Purely money-making, not even philatelic. Then Royal Mail took to selling some of these private productions through their Philatelic Bureau adding some sort of legitimacy to them, with the inevitable next step being that Royal Mail produced similar sheets under their own name at a much lower selling price but still over 3x face.
What was potentially a good idea for business advertising is probably the worst thing that has happened to British stamps in recent years.