cheapo dummies are definately the way to go!
Sleep school told me to get the "cherry" (round) dummies for my son, as they don't fall out of their mouths. He still uses them now. And if we lose one (like when he threw it into the zebra enclosure at the zoo last week)... it doesn't matter.

Also... is there any chance your DD has any wind in her tummy?
I've got a 5 week old, who is being an absolute angel (compared to my devil son).
She normally goes to sleep really easily... but I have found that if she wakes up too soon... she has an upset tummy and I pop her over my shoulder, rub & pat her back and oila - burp! Then she goes straight back to sleep. At first I was trying to feed her... but I guess that made the problem worse... until I worked out why she had woken up.