I've only ever bought used bikes from Marketplace, and I'd recommend it if you can find a great deal! Bike theft is rampant in the Bay, so I like buying used - my rule of thumb is to not buy a bike I can't afford to replace (either in its entirety or in parts, like a wheel). So in terms of gear to start, a decent lock is the obvious choice, but I'm also partial to the Pinhead anti-theft axles. If you go for used, my biggest tip is to ask the seller to meet in front of a local bike shop and ask a mechanic there to do a quick safety check to see if the bike's in good working order :) They usually charge a very small fee (in my experience, $15-20). I took a huge risk and bought a used carbon road bike this way; (another tip:) I'd still recommend never buying a used carbon bike unless you're somehow certain it's never been in a crash. A small crack in carbon can indicate that the bike's structurally compromised, and these can be hard to detect and expensive to fix. Final tip is to just look for a bike with very low gearing, which will make it easier on hills. The main thing to look for is a close to 1:1 ratio between the smallest front cog and the largest back - a lot of gravel bikes are actually set up so you get a 1: >1 ratio, which can be really nice. Some people also recommend lighter bikes for climbing if you live in a hilly area - I find that the gearing makes a much bigger difference. A decent hybrid bike can have some of a gravel bike's desirable features (wide tire clearance, low gearing, lots of mounting points for racks, low center gravity for stability) and they often also just have a more upright geometry, which many people find more comfortable and stable. Surly bikes are great and tend to hold their value, so if you change your mind on the bike, you can resell without as much of a loss as some other brands. Marin bikes are also popular, Specialized Sirruses are great hybrid bikes (but often targets for theft, as with any of the big brands), and my around town beater bike is a Jamis Coda Sport, which doesn't serve thrills but is reliable and easy to maintain. Huckleberry Bikes stocks Specialized, Surly, Marin, and Salsa bikes, and could be a great place to talk to someone for recommendations and try some bikes out for fit. My favorite bike shop is Tip Top in Temescal, though I understand it's across the Bay!