I've been going to this store since it was located on 6th Avenue, before the fire, and it has never failed to provide me with far too many hours of browsing and too much money I'm tempted to spend! They have the largest sci-fi/fantasy section of any of the used-bookstores in town, as well as a HUGE variety of other books.
Be sure to check for the Dollar sale books.... they're usually tucked in a back corner, and feature books that have been in the store unsold a long, long time. Some of them are such gems that I really wonder why they were overlooked so long!
Besides books, Halfprice features computer software (and it's not even prehistoric software!), music (CDs, tapes, and LPs), tarot cards, calendars, bookmarks, and many other items. They even have a calendar you get at the end of the year with coupons in it, for each month of the next year.