Coffee or dinner for first meeting???

Hi all,
I'm new to the forum. Please help.
I'm gonna ask a girl out next week.
I want to invite her for dinner. However, I read somewhere about tips for first date that "never invite to dinner, invite for coffee".
I don't understand the logic. Dinner takes longer and I feel it's more intimate.
The only reason for coffee is that it's cheaper and in case the relationship doesn't really get serious and your first date turns out to be your last, you won't regret for the money that you have spent.
Could you tell me what's the better choice.
Other guidelines and comments on the 1st meeting will also be appreciated.
Thanks
Tom