The total cost of a ruby ring is divided into the cost of the main ruby and the cost of its setting.
If the ruby ring in question is set with a natural, untreated ruby weighing around a carat, the ring will start out at prices around $1,500. This is also assuming the faceted ruby is not a vivid red color, has visible inclusions, and has modifying hues of orange, purple, or pink.
For a nice red, untreated ruby the price of the stone alone will reach at least $3,000 or more assuming similar quality (weight around a carat, included, dark).
The general rule of thumb for setting a ruby (or any other gemstone) is that the cost of the setting does not exceed that of the ruby. A synthetic ruby will be much less expensive than a natural one, so much so that a plain silver band and the most basic setting costs might be higher than the price of the ruby alone. Note that the Natural Ruby Company only deals in heated and untreated natural rubies.
The least of the setting costs is usually the materials, even when using 18k gold. Costs mostly go towards the labor of setting stones into the ring. Rings with a lot more stones in them will have much higher labor costs too.
As illustrated above, adding the small diamonds makes the price jump dramatically even though the amount of metal is roughly the same. Even when dealing in 14k white gold, the price of the setting will not decrease by much. Again, the bulk of the price goes towards labor.
Even assuming the best prices, the total cost for an untreated ruby like R10824 above would come out to something around $2,000 at a minimum. If you are willing to use a heat-treated ruby, a price range of $1,000 – $1,500 is feasible. This pricing also applies to other types of ruby jewelry like a ruby necklace, or ruby earrings. In practice all these principles apply the same way.