it much cheaper to make them yourself.. I have made mums before for my family..
first of all you need to find out if you want it to hang on the shoulder or do you want a wrist mum.
and what is the occuasion it for, a baby mum for a new born, or for a game?
There are so many styles out there, and when you make it just because your is different from others tht ok, for it for personal taste..
you pick your colors you want to use, you can get the circles which you will need 2 of themat a craft store, the small ones are for small mums, the larger ones are for your larger ones.
There are also heart mums, which you can put about 3 mums on it I believe, not done a heart mum yet, so I would need the pattern to see how many mums for sure, but like I've said I think it will take about 3.. just put the mums on it and see how many it will take.
take the ribbon and cut 2 strips of each color very short and fold it over and staple it to the cardboard to make your edges
on one of the circles, the other circle you will hang the long strips.
Then get the trickets you hang on the ribbons as the last thing.
if you need any other advice just ask.
Plus making the mums can be fun and a enjoyment item for the person you are giving it to.