I'm looking to add a zoom. They all seem to be around that 8~24 or 7~21 range. There's the Baader Mk IV top shelf option (sub $300) and there's the basic Celestron (and re-brand similars) 8~24 options ($70 or so). Doesn't seem to be anything in between. I'm not sure the Lunt 7~21 is any different than a Celestron 8~24 really in quality, other than "brand" up charging. Is there a middle ground? Something $150 that is between the Baader and the entry zoom?
Pricewise, yes, but quality wise, no. There are the low priced ones, the Baader range, and then the high priced ones.
The Baader, BTW, is a middle-priced option, being far less expensive than Leica, Zeiss, Nikon, Meopta, and others adapted to telescope use from spotting scopes.
$250-$300 is a mid-priced eyepiece for a zoom. What's amazing is that the Baader is as good as it is yet is as inexpensive as it is.
There are other zooms equally as expensive that are nowhere near as good.
Some Zooms to ask about:
365 Astronomy Aspheric Zoom Zoom 8-24
Agena Zoom Zoom 7-21
Agena Zoom Zoom 8-24
Altair Astro (UK) Lightwave Zoom Premium Zoom 8-24
Astro Professional EF Flatfield Zoom 7.5-22.5
Astromania Zoom Zoom 7-21
Astromania Zoom Zoom 8-24
Baader Planetarium Mark IV Zoom w/click-stops Zoom 8-24
Celestron Zoom Zoom 8-24
Discovery Zoom Zoom 7-23
Discovery Zoom Zoom 8-24
Leica Aspherical Zoom Zoom 8.9-17.8
Lunt "Solar Eyepieces" Zoom 7.2-21.5
Meade Series 4000 Zoom Zoom 8-24
Meopta Zoom Zoom 7.3-14.6
Olivon Zoom Zoom 8-24
Olivon Zoom Zoom 9.5-19
Omegon APO Zoom Zoom 8-24
Omegon Cronus Zoom Zoom 7.2-21.5
Omegon Flatfield Zoom Zoom 7.5-22.5
Omegon Zoom Zoom 7-21
Orion Lanthanum Zoom Zoom 8-24
Orion Zooom! Zoom 7.2-21.5
Pentax XF ZOOM Zoom 6.5-19.5
Pentax XL Zoom Zoom 8-24
Russell Optics Zoom Zoom 8-16
Sky Mentor (Khan Scope, Canada) Zoom Zoom 7-21
Sky Mentor (Khan Scope, Canada) Zoom Zoom 8-24
Skywatcher Hyperflex Zoom Zoom 9-27
Skywatcher Hyperflex Zoom Zoom 7.2-21.5
Skywatcher Zoom Zoom 7-21
Skywatcher Zoom Zoom 8-24
Telescope Service Planetary HR Zoom 7.2-21.5
Telescope Service Zoom Zoom 7-21
TeleVue Nagler Zoom 3-6
Vixen Zoom Zoom 8-24
The primary difference you'd find, if you somehow got to review all the above zooms, is that the least expensive ones ($150 and down) all have narrow fields of view in the longer focal lengths.
There are also differences in eye relief, mechanical construction, et.al.
The likelihood is high that if you do a search for just about any zoom, you'll find some posts here on CN about it, or a generic search on Google may bring up a review on another website.