Keri, I did the Yeson thing last January and am very happy with it, but to be completely honest, I gained just as much from seeing a voice therapist who works exclusively with trans people. I've had 20 visits with her and spent about 2 grand, and beyond her helping me recover from surgery and build my vocal strength, I have learned how to speak in a way that is female and very appropriate for my gender. If I had to do it again, I would have seen her first, and then decided.
FYI, I've been living stealthily for almost 30 years, and my voice was the only thing that ever got me clocked in the past, and that usually only happened on the phone.
Just getting a higher voice but not changing how you use it won't deliver you the results you hope for. Voice therapy will cut months off your recovery if you eventually have surgery, and you will benefit from it either way.