what level? Associates, senior analyst, head of team? Also depends on the house. A blue-chip IB will be the best of the lot, but a good buy-side house is likely to pay more than a second rate sell-sider. I've never completely understood the economics of the sell-side 'tail' - ie forty analysts covering Vodafone, what value do those below, say, the top-eight possibly add? Working hours are very different between the two sides, too.
Bear in mind buy-side is usually a training ground for fund management while sell-side is an end in itself. This site will give you a bit of a clue:
www.efinancialcareers.com
EDIT: Here are a couple of examples:
Senior analyst in a 'hot' sector in a blue-chip IB. At their desk 7am latest (possibly much earlier on a 'news' day). Will finish sometime between 6pm and midnight depending on what's going on. Occasional weekend work. Pay, six figure basic and bonus of multiples of that. Certainly potential for a decent seven figure package, but more likely solid mid-six figure. If markets are bearish then low-to-mid six-figure range (or just sacked, LOL). Things took a bit of a knock in the post-Spitzer fall-out because it was difficult to link analyst pay to M&A revenues. Buy-side for a typical long-only type blue-chip fund managers - working day 8-ish to 6pm-ish, rare to work weekends. Probably similar basic but bonuses only to 100% or so. But most buy-siders want to be a PM, where the rewards are better and work much more interesting, and most funds are set up so their best analysts follow that route. Hedge fund buy-side analyst, somewhere in the middle of the two, both in terms of pay and hours.