Ever wonder why diamonds are so expensive or a shirt suddenly seems nicer to you after you see a high price tag on it? That's due to the two most influential psychological that influence value: Price and availability. Create the illusion of more value by placing a higher price tag on the value of your services at work, and limit your availability to others, which makes you look in demand elsewhere.
To get anyone to see you as more valuable, place higher value on yourself and portray it through manipulating the most powerful psychological factors: price and availability. Remember if you don't place a value on your services, someone else will. Beat them to the chase by asking for more than you normally would have. (This trick is often used in department stores where you see an outfit and sort of like it. But, once you see a high price tag on it, you'll instantly perceive it to be more valuable.) Also, play with the trick of scarcity. The more scarce something is - think diamonds for example - higher value we give it.