When it comes to security fencing, - the big question is... How long is your build going to take?
You can do one of two things. Rent or buy.
For our build it was way clearly cheaper to buy. I will post some numbers later...
Of course you have to dispose of the gates afterwards but you would not have a problem. Offering them for free... Our builder even offered to buy ours from us at the end of the build.
As it turns out though.... it's even better if you have a sister and brother-in-law in the building industry.... that offer for you to use theirs;-)