Rubies that have been enhanced by only heat treatment are becoming increasingly rare, and unheated rubies are even rarer. Nowadays, nearly all of the rubies on the market are treated to enhance color and clarity, although untreated rubies can still be found. For the most part, heated rubies are very well-accepted by the general public, but nowadays, most rubies are enhanced through 'fracture-filling' technique.
Heat-only rubies are excellent investment gemstones as they tend to gain value over time. With ruby sources and production slowly depleting, it may be hard to find heat only rubies in the near future. Prices for fine quality natural red rubies can be very expensive, especially gemstones with top color, clarity and cut, but when buying from the source, you can save thousands of dollars versus paying full retail at your local shopping malls.
It's pretty great having a whole lot of different gemstones to choose from. When doing crafts and jewelry making, it's great to have all kinds of options, and it's amazing how much cheaper it is to just purchase un-set gemstones and make the setting yourself, as opposed to buying fully-made jewelry already. It's also extra special since you made it yourself.