Originally Posted by Machka
Yes, but you don't have to go with the most expensive stuff out there! My panniers (one set - that's all you need) cost me $100, my Carradice cost about $100, and my handlebar bag about $30. The racks (front and back) were in total about $30. TOTAL: $260 for the whole setup.
And if you question the durability of all that ... I have toured (in Europe, Australia, Canada, and the US) a total of about 18-20 weeks over the past two years with those items, and I've done most of my riding (approx. 10,000 kms a year) over the past two years with the handlebar bag, and the Carradice. In all that time, the mount on the handlebar bag broke once, and was replaced for free by the company who made it, and I sheared a bolt on the front rack, which was removed and replaced for free by a friend of a friend.
$260 is still in the range of a trailer (I didn't pay that much more for mine). Expense is kind of a wash. Weight advantage, on the other hand, would go to panniers. Durability? I think panniers and racks might have an advantage there also. Early BOBs broke the forks with regularity. Not good if you are in the middle of no where.
You can certainly go cheaper than the Tubus and Ortlieb but I was changing all of my touring gear (other stuff was way old and not waterproof any more) anyway so I went with good stuff. Not sorry I did. YMMV.