Just got engaged - can i say this?

What you've written ther sounds fine - that way it gives them the perfect opportunity to jump in and say "well we wanted to talk to you about offering you some money" and if they don't then you can assume they won't be paying for anything and can just continue with the plans according to your own budget. It's also normal for you to talk to your parents casually about your finances, especially in a wedding, so I don't think that it would loook like you were deliberately bringing it up in order to get help from them. I think nowadays it should be assumed that the couple will pay for everything, and the parents can offer to contribute if they wish, as opposed to it being assumed that they will pay, which is very unreasonable in 2011.