Is this the last volume you need to fill the hole in your complete set? If ‘yes’, then you likely already know what these are worth and whether it is worth it to you. If ‘no’, and you are merely hoping it might be worth buying because it is “old” and “rare” (hint: it isn’t), then walk away.
My (useless) advice:
If you are “tight on money”, and the only reason you are buying this is because you think it might be worth more than what you pay, you probably shouldn’t be speculating.
It’s a common book.
If anyone is collecting these, the best way to do so is to buy all of them in a complete set. You’ll never get a matching set by piecing them together.
I’ll say again: a collector should never buy a book solely because they think it might have a chance of being worth more than what they paid. That’s not collecting. It’s speculating. And you need to know what you are buying/selling if your goal is to buy to sell.