Harrow Deck: Price 100 gp; Weight —
This is a traditional fortune-telling deck of cards used by soothsayers and seers. Some harrow decks are elaborately illustrated, but most are parchment or paper cards with hand-painted images. Harrow decks are often handed down through generations and treated with utmost care by their users as a result.
The Harrow Deck description even states that it is a kind of fortune teller's deck. Bolding is mine.
Fortune-Teller's Deck: Price common 1gp, quality 25gp, masterwork 50gp;
This deck of illustrated cards is used by those in tune with the spirit world to predict the future—and by charlatans to take money from gullible or desperate people. A common deck only has simple drawings on parchment scraps or simple wooden plaques. A quality fortune-teller's deck is usually of quality wooden plaques with painted color images; it is suitable as a focus for the augury spell, and provides a +1 circumstance bonus on Profession (fortune-teller), Profession (medium), and similar Profession checks. A masterwork fortune-teller's deck may be wood, ivory, or even metal, with painted or carved images and often highlighted with gold inlays or tiny gems; it has all the benefits of a quality deck, except it provides a +2 circumstance bonus on the listed skill checks.
If we assume that a deck of harrow cards IS a fortune teller's deck, would it provide a bonus on skills as a quality or masterwork fortune teller's deck? It's cost is double that of a masterwork one.
Or would you, when playing a varisian harrower or con artist need both, a harrow deck and a masterwork fortune teller's deck to gain the benefits and stay true to your ancestors?