Do you have a smart phone? If yes, don't waste your money on a dedicated caller...
I started predator hunting when the callers had cassette tapes...it sucked and I broke/ruined several. When packaged callers with solid state electronics and better speakers came out, I was totally amped. Now I do not rely on electronic calls alone. I use coyote, rabbit, turkey, even goose mouth calls, but in the blind with a remote speaker, an electronic call is nice. I have used Johnny Stewarts, Primos, FoxPros over the years and I have spent some good money on them, but I do not own one now, nor will I ever again.
I have 3 different free apps on my smart phone for predator calling. I play those through bluetooth to a weatherproof 15 watt speaker ($50). It is every bit as good for my uses as a $300 to $500 caller, and I can use it in other applications. My typical set-up is to put out the blind and set the speaker in brush about 50 feet away. Then I go about 10 feet away from that and put up my furry spinner decoy. Sling the rifle and walk (based on wind) about 1/4 mile from the blind. I turkey or rabbit call a bit walking back to the blind and then when I get close, I mix a coyote call with a wounded rabbit/turkey/etc. and slip into the blind. Works pretty good. I called 3 coyotes in the other day sitting in the back of my truck with the speaker on the roof. The closest one came to 20 yards.
So while the dedicated callers had their place, bluetooth speakers and the quality of them and the calls on the apps is much simpler, and better than all the calls until maybe you pass $400 or so. The only caveat, you have to turn your cell phone to airplane mode, then turn on bluetooth or you risk a phone call screwing up a charging coyote...ask me how I know.

For me, the range of the bluetooth and the volume have been fine. There are more powerful speakers and bluetooth boosters to increase volume and offset, but I have not needed them. I do also keep a USB battery ($30) to charge my smart phone in the blind, and I have needed it a few times. Never had to charge the speaker.