Value of mint condition first pressing of Sgt. Pepper?


I have a mint condition first pressing (I think) copy of Sgt. Pepper's Lonely Hearts Club Band.  Vinyl is shiny and plays flawlessly, jacket is shiny with few indentations, and insert looks like new.  Any idea how much it might be worth.  Also, any idea as to how much value something like this gains over the years?  I'm thinking of giving it to my granddaughter (age 4) for her to cash in when she graduates high school.
Any input will be greatly valued.Russ
rustler
I'm with GK on this one. 

As for value, doesn't have to be first pressing to be worth a lot. Just has to sound good. Really, really good. https://www.better-records.com/product.aspx?pf_id=beatlsgtpe_1910_1
thanks to everyone so far.  the album has been in my possession since July of 1967, so geoff's input isn't appropriate.
Mine is stereo, not mono, and I'll check it out and take notes after my granddaughter opens it on xmas eve.
I’ll give you $25 no questions asked. You could always listen to it. 

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.