Early stereo LPs

The holy grail for UK record collectors is probably a stereo first pressing of the Beatles first LP, Please Please Me. It's worth anything up to £5,000 but sadly I haven't come across one yet. Even the second and third stereo pressings are well worth having, but again I have yet to come across one.
It's quite surprising that so few stereo copies come to light, as by 1963 stereo was quite well established. But it's not uncommon for stereo copies of LPs of the early sixties to be worth a lot more than the mono version.
I bought a couple of 1960 stereo LPs yesterday (in superb condition), both of which have quite a premium in value compared to mono copies. One of these was Elvis Is Back which in 1960 became the first Elvis LP to be issued in stereo in the UK. It's worth 50 per cent more than the mono version. The other was Cliff and the Shadows' Me and My Shadows, also from 1960, which, though less valuable, still carries a premium for stereo. Both of these are currently on Ebay if anyone is interested in bidding!
The Rare Record Guide shows that stereo copies of many LPs throughout the early sixties continue to have a greater value than mono copies. So most stereo Tamla Motown LPs are worth a bit more than mono, as are LPs by the likes of Ray Charles, Ben E King, Sam Cooke and Roy Orbison. The difference in value isn't very great and in some cases stereo copies are just as plentiful as mono ones. And of course many rock and roll LPs are not included as most of these were recorded in good old mono. By the late sixties most LPs were being released in stereo only, and although stereo copies of earlier LPs may be worth more, there are many cases where the stereo versions were inferior to mono. And don't get me started on 'stereo enhanced mono', which was an abomination.