Buy it.If you want to read it,buy it.In the past there have been a few times when I have dithered over whether to buy a particular book only to find that when I make up my mind it has gone out of print.I don't know this book or how old it is but I wouldn't take the risk.
It's available to buy but if you really don't want to, your library will be able to request it from another branch that has it (usually for about 50p).