Traditionaly hazel stakes were used, but many people now use the fibreglass poles, I agree the ones from Magnum are fantastic poles, but if your tight-fisted like me, you wont pay for them. An alternative is the poles from brinded at £1.75 each for a 2'6" or £2.25 for 1 meter.
I use a mixture of hazel and aluminium for my traditional nets, but fibreglass poles on my quickset nets.
Try a steel stockholders, you should get a 4 meter length of alumiunium 3/8" round for about £8, i got 5 poles out of a 4 meter length, they are 3 foot long. When you cut the length down, cut it in an ang