I havent thought about a tiara yet- but i have been offered to borrow one- that my cousin used for her wedding a few months back as she said she paid silly money for it (like 200 quid) and obviously wont be wearing it again... so i have one if i need one ..
some shops where you get your wedding dress from - if you buy the dress you can ask for a deal ask for a free tiara-or some shops do do deals and offer a tiara of your choice for free...
DF gave me my tiara when he proposed and he got it from Disney I'm not sure who from Disney he talked to but I'm sure they probably have some nice selections
Here is mine. It is a BelAire. I got it at a bridal shop (not the one I got my gown at). I tried it on on one of my first shopping outings and no matter what I tried on after that I kept going back. It was more then I wanted to spend but it is the one that felt right.