Stereo U.S. pressings of SPLHCB are VERY common, and worth no more than any other album from 1967, and actually less than many others that didn’t sell well (there were a lot of SPLHCB pressed and sold, and then not played much---it’s not a very good album ;-). Now if it was the Mono version it would be different story, especially a UK pressing.
The idea that original pressings of classic albums are ipso facto worth serious money is a myth believed only by those who aren’t into collecting enough to know any better. By the time your granddaughter graduates high school, this LP will be worth even less.