The following is just my opinion. I'm a Buffy collector--props, weapons, original ad posters, some 6" figures and display environments, statues, and Sideshow figures. I don't collect any other Sideshow lines. When talking with other Buffy collectors, they're typically unenthusiastic about Sideshow's buffy line due to extreme lack of humans. A full 6 people who were core Scoobies at one time or another remain unmade (or so poorly made as not to count), and there's no sign any are going to get made anytime soon. Consequently, a lot of Buffy collectors feel no need to collect the Sideshow line at all unless more core humans are made, or only pick up a few figures and ignore the rest.
That's why I don't want to see a demon Anya before a human one. I think the whole problem with the Sideshow Buffy line has been Sideshow's over-emphasis on monsters and underappreciation of the huge popularity of good human character likenesses in the line. General Sideshow collectors who collect other SS figures probably prefer monsters, but most of the Buffy fans I know care far more about humans and many won't buy SS figures only because not enough human characters are available. They don't want to commit to the SS Buffy line knowing that it could end with major characters unmade. Some people wonder why nice sculpts like Vampire Buffy take so long to sell out, and why small edition exclusives like Der Kindestod are still kicking around after ages. The short answer, from talking to other Buffy-specific collectors, is I think the fact that they want to see more humans before they commit to more monsters.
We've only gotten good likenesses of 3 humans (Xander, Oz, and the Buffster herself) and two human-faced vamps (Spike and Angel); Willow is such a nonexistent likeness that she's a slap in the face and doesn't count, and Faith is merely passable so just barely counts. Counting Faith that's just 4 humans, or 6 human-faced characters including the vamps. Buffycentric collectors often wonder why we're getting many tiny editions of demons which sell smallish amounts and endless remakes of Buff/Spike/Angel without getting any of these humans in between, which would sell several times as well as Vamp Buffy or Der Kindestod in half the time:
Willow (a real one, not the existing craptacular un-likeness)
Tara (an OMWF Tara would sell out even a big edition)
Giles (of course)
Anya (not hugely popular nor minor, but a solid bet)
Cordelia (probably an Angel release now--long hair please so she can double for a Buffy Cordy)
Dawn (too underrated--she'd still sell 2000 or so quickly, much more if a good sculpt and outfit choice)
Kendra the Vampire Slayer (minor, but she'd outsell Der Kindestod briskly)
The Primitive (the first Slayer--she'd have crossover appeal to monster collectors)
Jenny Calendar (minor, but again Buffy fans would make sure she sells at least as well as Der Kindestod--add an Eyghon head as an exclusive and she'd sell like hotcakes!)
Glory (with Hellgod robes from The Gift as excl. accessory to hide articulation)
The Mayor (Box of Gavrok w/spider-demon-thingy coming out as excl. accessory)
Sure, there's this irrational concern that the line would die if we got all the core human characters. But that's not a rational excuse, because there are 6 core humans left, and a few more minor ones--plenty to last years when sandwiched between monsters, so why aren't we getting any anytime soon? There's also the likelihood that more Buffy fans would be drawn into collecting the Sideshow figures if more core characters were released, driving sales and interest in the line up across the board, inflating monster sales too. There's also no danger of the Buffy line dying just because all the main characters are made, simply because several of the core characters could easily support later alternate versions--for example, regular Willow, later Dark Witch Willow, and even further down the line a Season 1 long-haired Willow or a white-haired Chosen Willow. Buffy fans will gladly buy multiple good, unique releases of a character given some time between, so the idea that releasing core characters would kill the line doesn't hold much water. Releasing more core human characters would grow the audience for the line, not kill it IMHO. The 6" Buffy products are more popular than ever, yet every main character has been made and remade in many variants and multiple waves (except Dawn, whose first releases are in the current line). Normally I wouldn't bring commodity 6" figures into a discussion about luxury 12" figures, but Buffy is a special case in which the 6" collectors and potential 12" collectors overlap significantly given Buffy fan demographics.
Again, that's just my opinion as a Buffy fan who's increasingly less interested in the current direction of the line, and knows a lot of fellow Buffyphiles who are at least as disenchanted. Human Anya, please. Human Tara, human Dawn--just give us more good core human characters. The demon-of-the-week and rerun show the line has become isn't very conducive to winning a bigger audience for these figures. I know some will disagree with my positions, but hey, it's good fodder for constructive discussions, right?