stretch and creep and two different things.

stretch is something that will happen each time the rope is loaded.

Creep happens only one time and is the rope bedding into its proper length.

DSK 60 is a lower grade than DSK75. I only use 75 and if its really important I use 78 which only a few manufacturers can make.

Do not tie knots with this rope, they create a weak point and negate the use of a strong thin rope.

The brands shouldn't mean a lot but in reality i have found that Samson Amsteel Blue DSK75 is very good. maffioloi also make excellent ropes but they are hard to get in AUST.

As for prices:-

2.5mm DSK75 = 1.90 AUD
3mm DSK75 = 2.48 AUD
4mm DSK75 = 2.84 AUD