A discount. On already cheap as fuck commissions. Yes, $25 for a colored character pic is cheap. If you think that's expensive you can either: Go fuck yourself, or, find another artist. You know, for some of the people that have gotten several commissions, I might actually consider giving them a discount - but that's only if they're buying a LOT of pics.
In any case, dude asked for a discount. Why? Well because he wants four characters getting transformed in a sequence (he didn't say into what, or I missed it) and doesn't want to pay $25 per character per image.
Hint: Bulk discounts work at Sam's Club and BJ's because they can bring down the price for MASS PRODUCED stuff when you buy it in bulk. This does not work for commissions.
Why is that, you might say? Because you are adding more work for the artist to do, and wanting them to take less pay for it. Notice how this doesn't add up. More Work. Less Pay. Nope.
Why did he want a discount? Because he's a student and has to "watch his budget". Let me explain how the world works. I don't give a shit if you're a student or a billionaire. I charge those rates to give myself a fair wage for the work I do. If you don't want to pay it, for whatever reason you feel like making, you don't have to. But don't ask me to take less pay for more work because you can't afford it. That's both bullshit and stupid. If you don't have the money to pay an artist their wages for their work, you don't need to buying anything from them. You see if you are out of money, then YOU have to make the sacrifice, not the artist.
Some artists might be desperate enough to fall for this. This artist is not. And people that whine that custom artwork is too expensive: Well you can easily do the work yourself. Then it's free. (This is where they usually whine that they don't have the talent or the skill. This is then where I point out that if they don't have the talent or the skill, they shouldn't undervalue the talent and skill that artists have developed).
We were not born artists to give the world free art. (Despite the fact that a great many of us do in fact, display our art for free). But if you want the artist to make a custom piece of work specifically as you request it, you pay for it. End of story.