I've got Axiom Seymour panniers, which were about $40. They're not pretty the way more expensive panniers are, but they hold up to my usual loads, and are holding up to fairly heavy use. I also have a bungee cargo net that I use when I screw up volume estimates.
When I need to add more cargo capacity, I'm thinking "front basket". Load balancing matters, and that gives me an easy no pannier option. Knowing what I know now, I probably should have started with a front basket, *then* added panniers.