Each week, former sf.myopenbar.com editor Allie Pape brings you her picks for the best places to booze on the cheap in SF. This week: Three classy deals, two trashy deals. Have an event coming up? Want to share a tip? E-mail her.

1. Alembic's Half-Off Beer: We love the hip Haight bar Alembic, but our wallet tends to disagree after a round or two there-- a real shame, considering their vast beer selection. Luckily, there's some light at the end of this tunnel for suds-lovers: the Alembic's bottled beer selection is now half-off on Mondays, allowing visitors to drink in the gorgeous environs without the crowds or the markup. Another money-saving tip: they're now serving lunch, at significantly lower prices compared to their evening menu. (Monday nights at Alembic, 1725 Haight St., Upper Haight.)

2. Happy Hour at Bacar: Also from the "too rich for our blood, until now" files: SOMA hotspot Bacar has a new chef, and a new happy hour menu, with all their bar bites half-off. This means $5.50 sliders, $3 fries, and on Fridays, $1 oysters. To wash it all down, they're also offering $2 drafts, $5 classic cocktails, and selected wines by the glass. Poverty never felt so classy. (Daily, 4:30-7 pm, at Bacar, 448 Brannan St., SOMA.)

3. Late Night Happy Hour at Sheba: One of the many musically-inclined restaurants lining the gentrified Fillmore strip, Sheba Piano Lounge prides itself on its commitment to world music. Their new late-night happy hour reflects this, with a commitment to world drinking. Enjoy $4 beers from Ethiopia (St. George), Belgium (Stella), SF (Anchor Steam), and Portla--er, Germany (Widmer). $6 will get you a glass of Italian Pinot Grigio, Argentine Malbec, or good old Irish-Catholic Jameson. Spinning a globe and making a room spin, together at last. (Sunday-Thursday, 10 pm-12 am, and Friday-Saturday, 11 pm-1 am, at Sheba Piano Lounge, 1419 Fillmore St., Fillmore.)

4. Lexington Club $1 Margaritas: If you're not inclined to visit the classy establishments above, we have a pair of trashier places with absurdly good weekend deals. Up first: the Lexington Club, a Mission dive with a largely (but not strictly) lesbian crowd. They have $1 margaritas for an hour on Friday nights to fuel the girl-on-girl action. (Fridays, 9-10 pm, at the Lexington Club, 3464 19th St., Mission.)

5. Bar on Church 50-Cent PBR: We've previously featured the escapades of the crew at Bar on Church, who are always looking for new ways to ensnare sotted misers: their latest is 50-cent PBR on Saturdays, offered from late afternoon until early evening. Yeah, the ambience is like being inside a giant disco ball, but between this and the bottomless beer special, we have to applaud them for looking out for the little guy. (Saturdays, 4-8 pm, at Bar on Church, 198 Church St., Castro.)