Turbine has revealed a new feature that allows players(only Sorcerer and Bard) to exchange their spells with each other.This update will come out in a near future.

How will it work?

All Sorcerer and Bard trainers will have a new option added to their dialogue box: "I would like to exchange one of my spells for a different one." Selecting this option brings up the Spell Exchange panel. Spell exchange works in the same way as the Action Point system - select the spell you would like to get rid of on the left, and select the desired spell on the right. There is a cash price for each spell swap and you can only swap a spell for another spell of the same level. You can swap as many spells as you like, at any time you like, the only limit is how much money you have in your coin purse.

How much will it cost?

The following is an example of the pricing scheme. This is subject to change.

Level 1 Spells = 1,000 gp per spell

Level 2 Spells = 4,000 gp per spell

Level 3 Spells = 9,000 gp per spell

Level 4 Spells = 16,000 gp per spell

Level 5 Spells = 25,000 gp per spell

more for ddo here