Originally Posted by
jrickards
That's a long way and therefore, a lot of time.
The advantage of good quality (and not the least expensive) panniers is that if you don't feel you need them after this trip, you could sell them for a decent price and likely the "capital loss" would be less than had you purchased cheap panniers (and not been able to sell them).
Just my 2¢
I will double that to make it $0.04. OP: I would sock away a little money every day, week or whatever towards a good set that is going to last for a long time and will have a better resale value. $1/day for a year would get you very close to a full set (front and rear) of Ortlieb Roller Pluses. It would me more than enough for a full set of Roller Classics. And keep in mind that Ortliebs are at the high end. There are other higher-quality options that are less.