IMC, all sorcerers start with Eschew material components for free. The limit I set is 25gp.
Eschew Materials
Benefit: You can cast any spell that has a material component costing 1 gp or less without needing that component. (The casting of the spell still provokes attacks of opportunity as normal.) If the spell requires a material component that costs more than 1 gp, you must have the material component at hand to cast the spell, just as normal.
In our last campaign, my sorcerer had gotten imprisoned, and she tried to use suggestion, which has a component. The DM said I had none. I was quite angry, mostly because we hadn't discussed it before-hand. Which is why I try to make things very clear so that the players aren't surprised when the DM screws them over. I was quite upset that he had rendered my characters helpless. If I had known he was going to require me to use components, I would have gladly purchased eschew materials.