In the Exotic Mageware section of the Black Market, the simple, average, and complex spells for all colors can be purchased. In addition, Ancient spells may also appear for direct purchase without the intermediate step of the corresponding unique item.
In the most recent Blitz Server run for example, the Ascendant Ancient spell Heavenly Protection came on the market at a starting price of 5 billion geld. Generally complex and Ancient spells sell for a great amounts of geld.
Ultimate spells of course, are not available to off-color users in any way: they will never appear in Exotic Mageware.