It looks like you’re trying to assess the risk involved in spending for a new instrument which you might not like or might not be able to play. From my perspective, there doesn’t need to be much actual financial risk involved.
You want to maximize your likelihood of success with the flute while maximizing your ability to resell the flute if things go awry.
Maximizing your chances for success would include purchasing a flute which is highly playable and, should you have concerns about your hand size, small-handed. When I began, I did so on a plastic flute which was just not very rewarding to play and which had enormous hole spacing that gave me cramps–I was frustrated and encouraged NOT to play it. However, the moment I picked up my Casey Burns flute, I was immediately able to play it, it was highly rewarding, and it was a perfect, natural fit for my hands.
I believe that it’s going to be easier to learn if you get positive feedback from your flute and if it is not a struggle, and if you are going to dislike the flute for any reason, it should not be because of the flute itself, so I would recommend a Casey Burns Folk Flute.
That is a good financial choice, as well, because they are priced reasonably. While they aren’t less than $100, you can re-sell the flute fairly easily should you decide to give it up or to upgrade. The Folk Flute is readily available, so you won’t have to wait an inordinate amount of time, and Mr. Burns is great to work with.
Another good choice may be a Doug Tipple.
Having gone to flute in mid-summer, I can tell you that it isn’t impossible. There is that matter of holding the flute to get over, and that may take a few weeks. The instrument is big, but you’ll get used to it before you know it. Lots of instructions available on the web about that.
Embouchure is more problematic. With the flute, you actually have to shape the airstream yourself and direct it appropriately. This takes some practice–some trial-and-error discovery. You’ll go through a number of stages as you develop.
Someone told me it would take three months to get a consistent sound from the flute, and they were right on the nose. It took me three months almost to the day to get a predictable sound on demand. It took longer to be able to play notes in sequence and have them come out anything like I imagined them to be. It took five months to discover how to get a solid, vibrant tone, and another month to be able to do it deliberately. It has only been in the last few weeks that I have been able to sit down with something in my head and transfer it to the flute, and be able to control and change the tones as I wish.
Now, I’m a little “slow” coordination-wise, and I’ve noticed that other beginning fluters on the list seem to make more rapid progress, so you might do better. But, learning to play this kind of flute seems to take a while, during which you make infinitesimal bits of progress. You have to be patient, practice, be happy with what little progress you may be making, and have faith that things will improve.
A teacher is probably a fine idea, but I do not have one. It’s not impossible to learn without one. Many people on the list are very helpful and willing to offer suggestions if you ask. The archives are very good, in fact. The MadforTrad flute CD is handy in that it allows you to hear and see Seamus Eagan playing the pieces you’ll learn, so you can use that as an ideal.
Good luck!