I've seen prices from $120.00-$300. I have a preference for Duracoat, and many claim Cerakote is better but I can't see a plug nickel's difference between Dura and Cera. I charge my customers $200 to refinish a handgun (sometimes cheaper). I know my prices are on the high side, but I'm not a full time coating operation, so I'm not "optimized" like some of those outfits are for refinishing a high volume of guns. A proper finish takes time, and honestly it's not a job I enjoy doing. Since I don't much like coating (or much any other finish work), I figure I might as well at the very least make it profitable for me. And I do my best to make sure my customer gets a top quality finish.
But I've found Duracoat (and Cerakote too) to be superior to most poly-coat spray on finishes. I don't make outlandish claims that it's "the best" finish, or tougher than anything in existence. What I tell people is, you won't find a higher quality, tougher finish for the same or lower cost anywhere. Duracoat gives a lot of value for the dollar. It's a good looking finish, it resists wear very well, it's good against most chemicals you're likely to encounter, it's very good for resisting rust; and applying the finish doesn't break the bank. For the money you spend, it's an excellent finish.