I've been searching for a moderately priced treble boost pedal, the ones I've run across range from $160-250. I looked at Boss GE-7 and I'm wondering if that willl do the trick.
a graphic EQ does a different thing to a treble boost.. it's kind of hard to explain what a proper treble boost does exactly...

the only thing i'm aware of that's marketed as a "treble booster" that doesn't cost a fortune is the EHX screaming bird, which creates a very weird scratchy filter effect that sounds almost like when you run a wah pedal full tilt, nothing like a rangemaster or anything like that... the screaming bird is kinda cruddy with single coils, but can be very nice with humbuckers if you roll back the tone on your guitar a fair amount and/or have a very dark sounding amplifier. Definitely not something anyone should purchase without trying out first.
Rig Winter 2017:

Fender Jazzmaster/Yamaha SG1000
Boss TU-3, DS-2, CS-3, EHX small stone, Danelectro delay
Laney VC30-112 with G12H30 speaker, or Session Rockette 30 for smaller gigs
Elixir Nanoweb 11-49 strings, Dunlop Jazz III XL picks
Shure SM57 mic in front of the amp