There are many Reso's out there at 700 bucks.
You have to play them.
The Epi Bisquit is a $300 reso that honks like crazy. I've played reso's at three times the price that sound like dead acoustic guitars. You want that great resonator honk.
I paid about half of $700 for my Dobro Hound Dog........
..and it has a nice pickup inside. It does not have the volume and tone knobs. I have to control the tone at the amp which I prefer.
Go try as many as you can. It really helps. Resonators are unique..you have to hear each model. It's a ton of fun.
John