Hi Zarayaa! My change was small. They asked me to explain why I needed more funding than they usually provide for a particular item, and if I didn't need have a special need to justify it, to reduce the request. I didn't have a special need, so I reduced it.
I don't think the amount you ask for plays a part in whether or not they'll fund your project, unless your requests are outlandish. If they decide to fund your project, they will work with you on your budget to make sure you have what you need, but also that you're not asking for things they don't typically cover. Here's a really helpful blog post they wrote a few years ago about their perspective on budgets: http://blog.wennergren.org/2012/03/grant-season-journal-part-5-preparing-your-budget/.
As another example, there was a person on this forum last year who was asked to justify including transcription and NVivo software in his budget, which was probably a pretty significant chunk of his request. He wrote back and explained why he needed it, but they still asked that he remove both from his budget in the end, so he did, and he was funded.
From what I've heard from people who have won the grant and from what I've read in these forums and over at Academic Wiki, I'd say that definitely pay careful attention to putting your budget together, but don't stress about whether the amount will impact their decision to fund you or not. If they decide to fund you based on the project itself, they work with you on the budget.