where (generally) are you? Do you know for 100% certain that the CWD fits your horse well?
Changeable gullets aren’t a magic bullet for a horse who changes shape. It MIGHT be if the change is really limited to the front of the tree, like weight loss/gain beside the withers and around the shoulders.
IMVHO, a nicer solution is a saddle that fits her shape very well right now, and then as she loses fat/gains muscle, you can change the thickness of saddle pads and/or use shims. OR, if she’s really not overweight, just under-muscled, then a saddle that fits her shape but is 1-2 sizes too wide.
This means you can impact the fit all around, not just up front.
For that reason I might try to invest in an independent saddle fitter. There’s just so much more to fit than whether it clears the withers.
CAIR flocking - some horses love it, some hate it. Some riders love it, some hate it. That’s why reviews are so mixed, and aren’t something you can base a decision on, it’s something you just have to try for yourself and the horse.
That said, Bates and Prestige mentioned are relatively close in shape to CWD, at least from my experience. I used a Bates Caprilli (and a few gullet changes!), then an Ansur, then a Balance saddle, then tried a CWD (fit horse, not me), and finally ended up with a Prestige dressage saddle after also trying a Prestige CC saddle, and they all fit the horse.
I also trialed, and ended up ordering, a Black Country Quantum X (hoop tree version of Quantum).
Finding a nice quality, well-used Prestige can be hard, but I’ve done it twice, and you can find one if you’re patient and know what you need size-wise.
BC is a nice brand to look into, lower pricees than Prestige and CWD, maybe similar to Bates at least the last time I was looking around
Budget-friendly means high quality brand, well-used. There’s really no such thing as a 'starter saddle" unless you’re talking about something that’s really cheap when new, and that’s not a saddle quality you want.