So there’s no price on the back.
Is there a price of 2/6 in the bottom left hand corner of the first inside page (usually this is opposite the title page)? Sometimes this price has been clipped out – when the book has been given as a gift. If so, your book dates from between 1965 and 1967.
Was your book published with glossy boards? Then it probably dates from after 1983 and that’s about as far as you can take things. Books printed after 1983 aren’t normally considered to be collectable.
If neither of the above then your book probably date from the mid 1970s to early 1980s. It’s hard to be precise without seeing it – but books of this era are very unlikely to be considered rare or collectable.
I’ll also add that you might be able to extract a little info from the presence of an (i)sbn number:
1966 ish – 9 digits
1970 ish – 10 digits
2007 onwards -13 digits
(Now, to find out if your vintage book is a first edition, you need these pages)