Can you wait and buy it when you arrive? YES
String or cord can serve a multitude of purposes. You should go for man made fibre if possible (paracord is good but a bit overkill for most situations) rather than natural, because it is stronger, lighter and not affected by water. 10m is enough for most purposes, but I always reckon that a bit more is handy.
Washing line, repairing broken rucksack straps, replacing shoes laces, holding up loose trousers (you lose weight if you get the runs!) , holding doors shut at night, fastening bags, hanging curtains in hotel rooms, spare guy ropes for tents, hanging clothing off the floor in rooms, hanging mosquito nets and making a loop to keep your sunglasses round your neck.
If you forget the string, or run out, you can often use creepers or vines. Test them to make sure you aren't alergic to the sap, and that they are flexible. Vines over 3mm wide can often by cut down the middle with a sharp knife, doubling your bindings.
|Having run out of string on Bushara Island (it was all being a washing line), I made use of a few vines to lash together a support for my camera and solar charger...|