How much should I sell these cards for?

So I have a few Trenton Roberson signed pokemon cards. If you don't know he's the 2008 junior pokemon champion. I have a darkrai Lv X, Garitina, and 2 others I can't seem to think of the name of them right now. Just please tell me how much these signed cards are worth. Thanks in advance!!

Those sound like they're from this deck: http://bulbapedia.bulbagarden.net/wiki/Intimidation_(TCG)

They aren't worth very much individually, maybe $0.10 per card, as they're not sought after. If you had the whole deck still in its packaging it might be worth $11 or $12, but that's about what it sold for in the first place.

Keep in mind that these "signed" cards were mass-produced.

No sorry I didn't clarify this. Their personally signed. I went to a tournament and he a utogrpahed them for me. Their not from the champion decks

Most people who have cards signed actually devalue them. He may be a Junior 2008 champion, but he's a junior. Most people are concerned about Masters, since they're more developed young adults to adults playing the game. If anything you should keep the cards if they have sentimental value to you as you won't get much money for selling them.
Sorry to crush your hopes of rollin' in the moneyz.

What Renpuu said. Autographed cards usually become devalued unless they're signed by the artist of the card, and even then there's no guarantee it wouldn't be devalued. Autographed cards are more for sentimental value or just to give your collection a unique card.

Why don't you try $20. Hopefully he sees your auction and gets to see someone still remembers him cause I never heard of him.
juniors and seniors have it easy in tournaments with their low attendances. I'm not impressed by them unless they really came up with their deck on their own and it has to actually be a good deck.