I think a pricing guide could be a disastrous idea.
Value is entirely subjective, and it should remain that way. Making a public document that's easy for people to grasp and disseminate will only lead to inflation of popular villagers and a drought of unpopular ones.
The issue, as I see it;
1) Villager prices are spiking because money is easy to accrue, but not everyone will pursue the easiest money-gathering venues. Thus, a three-class economy emerges; top-tier dupers > power traders > non-traders/non-TTers/low-end turnip marketeers.
2) Villagers are primarily gained through alt/spare towns that reset and cycle through to popular villagers, giving a weak, but steady supply of super-rare ones and more common ones alike.
3) 16-villager cycle rule keeps supply in check from main towns.
4) Popular interest keeps supply in check because not everyone who gets an expensive villager will sell them.
5) Everyone is after a handful of villagers with about 20-30 that are also of interest to some and have occasional price spikes, as well.
To release a pricing guide does nothing good for anyone in this situation, however. Prices will go up because everyone will expect the highest of prices; everyone will want to beat that 150mil auction for Ankha, or that 38mil auction for Tangy, or expect the "average" of 30mil for Tangy to go higher as fewer are resetting their alt towns and fewer are cycling them out of their main towns (as we can expect to see in the coming months, I'm sure).
So what does the pricing guide do, exactly? As far as I can see, it only promotes inflation. It will not help cap inflation whatsoever, and that should really be the ultimate goal anyone hoping to impact the market should seek. Nobody is going to try and sell a villager and say "I'm setting the buyout for Tangy at 25mil, which is under the average price, because I wanna be nice.

" Why? They're smart. They've found a pricing guide because they want their money's worth, not to be fair. There are nice people out there, sure. But most people are either looking for a good price, or are giving villagers away. A cut down the middle, of pricing fairly under the market average because of some pricing guide? That's unrealistic to expect.
So if there is a pricing guide, there will be only one group of people benefiting; sellers. And that's not good.
Now, that's not to say sellers shouldn't get good prices!
But if someone is happy to take 2mil for Tangy while others take 38mil for her, then why should the 2-mil Tangy person be made to feel ripped off by seeing a pricing guide that tells them they vastly underpriced?
After all, they were happy to accept that 2mil!
And they don't necessarily NEED 38mil, do they? Perhaps to compete in this inflating economy, but the best thing for this economy would be lower prices, which would lead to fairer access to all things for those who are in the lowest class of my proposed 3 classes.
But if a pricing guide is readily available, suddenly 2mil Tangy becomes 30mil minimum starting bid Tangy, and nobody with a less-than-duping/power-trading income will be able to compete. Meanwhile, this person who would've otherwise been fine to take 2mil is now sitting on 38mil and they don't know what to do with it.
So what do they do? Spend it too freely, paying too much to get items extra fast, or to outbid someone else in a villager auction. Inflation keeps happening, and even more rapidly because there is no check on lazy sellers - the lazy sellers, who help to slow down inflation by being ill-informed, are now instantly as savvy as the researching, active sellers - thanks to the price guide.
And so, villager prices keep soaring, and dreamies become more impossible for the little gal.
"But what about buyers? Shouldn't they know the value of what they're paying for?!"
But they do! A pricing guide is useless to buyers by default, because the buyer determines how much they're willing to spend on something. I, as a buyer, always have the authority to set my own price - a guide will never help me do anything but plan my savings, but that's not really that useful, now, is it? I should be saving up anyway!
So if, to me, Cole is worth 6mil, then I'll bid that much if I must, even if everyone else is only paying 2mil on average. Because what does an average price matter in an auction? It might curb bidding to 100k increments or something, sure, but at the end of the day, I'm not going to drop out of an auction because it crept over the average price - I'm going to keep pressing on, but because of the price guide that says he's worth 2mil, I'm going to feel a little ripped off.
So from my point of view, a pricing guide seems like a good idea, but I think it'll cause more problems than it solves.