The question most typically asked about books-on-tape at Border's Bookstore in Towson: "Is it abridged or unabridged?" Most are abridged. Two cassettes and three hours is the most typical length says community relations chief Chris Brenchley. And why? Price and length dictates: For example, a three-hour recording costs the consumer approximately $17. An unabridged title, on the other hand, can run 12-20 hours and cost $50. The decision, to abridge or not, is made on a title by title basis: "Dark Rivers of the Heart," by Dean Koontz, runs 20 hours and retails at $49, the hard cover is $24. But Barbara Michael's upcoming title, "Stitches in Time," due for release in May, will be available in
hard cover and a three-hour two-cassette, abridged, audio version.