BSP didn't issue any hardcover trade editions of Bukowski's titles until Burning in Water... and I would guess that the market for Bukowski at the time didn't warrant the expense of putting out a lot of hardcovers. When Bukowski did a booksigning in '86, the store ordered most of his available titles in hardcover to sell. BSP sent first printings of many of the titles, some of which had been issued 3-5 years earlier. I guess that hardcovers weren't big sellers for them at the time.
The paperback was $4.00, signed & numbered was $15.00 and the copies with paintings were $25.00.
... and in full disclosure, "Burning in Water" was not really a "Trade" edition, but a "library" edition. These were made and marketed to libraries and not sold to stores. This explains why the library edition is harder to find than the signed edition. It was not until "Factotum" that they published a full on trade HB edition.