At this very moment, for a Grille Ausf. M to my door via eBay, ~$32 US for Alan or ~$53 US for Dragon. 
A sealed Dragon Grille Ausf. H is already in my closet. Yay younger me. 
Cue chorus girls:
Why doesn’t he build what he has?
Oh no!
Gotta buy a new one!
Oh ya!
It is awesome that almost every model is out there, somewhere, just waiting for the right person to build it. 
(More probably store if for free for someone else.)
Are there issues with the Dragon kits?
Kinda funny. Have a bunch of Cyber Hobby and Dragon Panzer 38(t) based models. Never built any of 'em. Vaguely remember TriStar Panzer 38(t)s getting better reviews. Built the Hobby Boss / TriStar Panzer 38(t) Ausf. E/F. That was a really fun model. You gave the Tamiya Panzer 38(t) Ausf. E/F a really good review. Want one of those. Really looking forward to the coming Hobby Boss release of the old TriStar Marder III Ausf. H.
Does anyone else kit the two Panzer 38 type Grilles?
The Dragon Panzer 38 Grilles are both VERY good.
I pity you… 
Actually, I envy you as I scratch built mine using their Marder III Ausf H as a base kit well before they released their Grille Ausf H - I replaced the inaccurate Dragon Marder with Tristar’s.
You are an extremely good modeler and your desire for accuracy is very high.
In the specific case of the Marder III Ausf. H and Marder III Ausf. M, models by Hobby Boss (TriStar) best fit my needs. I avoided the Dragon offerings for those two, very probably for the same reasons you did.
I have 5 Dragon Panzer 38(t) based vehicles in the closet:
Panzer 38(t) Ausf E/F
Aufkalrungspanzer 38(t) mit 7.5cm Kw.K
Flakpanzer 38(t) “Gepard”
Geschutzwagen 38 H fur s.IG 33/1
7.5cm Stu.Kan. auf Pz.Kpfw. 38(t)
On the subject of the 38T based SPGs, I’m surprised Hobby Boss hasn’t taken advantage of having the bare bones with their Marders, to expand the range.
They bought out Tristar. They are using the moulds but have not expanded on any of the range they acquired. Based on the short cuts Horror Boss takes with their own releases, it is probably a good thing they have not played with the quality moulds they have.
Hobby Boss, I Love Kit and Trumpeter are owned by the same company. I Love Kit is also a brand that releases other manufacturer’s kits.
Hobby Boss is not bad on all accounts: I love their Sd. Kfz 222 series (I build only one, but since all versions are similar and kits contain parts for multiple versions, the other ones can not be far off the one I build… )
Is it one of those Tristar re-releases under Horror Boss? Tristar kits were superior.
I like TriStar 
Ah, the devil is in the details.
Thanks!
