Kriega is very well made stuff but you're right - it's pricey. And overengineered unless you're going RTW which let's face it most of us ain't. And consider this - most stuff is adequately waterproof and can be made completely so with the use of a handy, cheap "rubble bag" liner, available in packs of ten from your local supermarket. I commute to work by bike, if I need more than will fit in my rucksack (which is, er, a Kriega but that's not the point!) I generally use a barrel bag, secured with a pair of Rokstraps attached to the handy hooks each side of the pillion. Once off the bike, I then have a useful holdall to carry all the stuff I bought with me. Simples!