Limit on how many candies you will receive?

Every Pokemon you transfer will only give you 1 candy when you're transferring it. Even when that Pokemon is evolved.

When you catch a Pokemon you will always get 3 candies.

When you get a Pokemon from an egg, you normally get a much higher number of candies with it for free. Compare this table, from a reddit thread:

 2 km eggs:  5 to 15 candy
 5 km eggs: 10 to 21 candy
10 km eggs: 16 to 32 candy

You always get one candy for transferring Pokemon, there is nothing like a "Power-Up" to change this.

You get varying amounts of candy when hatching an egg, 3 pieces when catching a Pokemon, and 1 piece when transferring a Pokemon.