Kovan Ether (KEth) have no market value, they can be obtained for free and are meant for testing purposes only.
Kovan network faucets provide Kovan Ether to legitimate developers willing to deploy and test contracts on the Kovan network. The faucets also prevent malicious actors from obtaining large amounts of Ether.
You can instantly get 1 KEth per 24h per GitHub account by visiting https://faucet.kovan.network/ and submitting your Kovan address.
You can receive Kovan Ether using Gitter (uptime is not guaranteed, and you may have to wait for a verifier to respond). Simply comment with your Kovan address in the following Gitter channel:
https://gitter.im/kovan-testnet/faucet
The above faucets allow to get 1-3 KEth.
Many transaction can be made with small amounts of KEther. For a typical contract transaction requiring 100k gas at a price of 20 Gwei, you can make: 1e18 / (100000 * 20e9) = 500 transactions with just 1 KEth. If you need a large amount of Kovan Ether please open an issue in this repo explaining the reasons for you to request more. Exception will be handled on a case by case basis.