clarry: Isn't that a bit too reductionist?

First because the prices range from free to a few dozen bucks. It doesn't seem exceedingly expensive to me?2.

Second, it's not the technology that costs money. You can make a fancy first person fantasy rpg using off the shelf parts, but you're going to need a content mill if you want to fill the world with things.

If you need a story, visual art (backgrounds, characters, animations), music, voice acting, programming, q&a, testing, translation, etc. it can get expensive. Lots of people involved, of course they all want their share. I'd say it's roughly proportional to production values, unless it's a labour of love like Narcissu. Oh, I wish we had that on GOG (even if it is free). I love Narcissu.

You can now pick up "indies" like Ne No Kami or Highway Blossoms for about five bucks but they're not at all in the same league with the likes of Da Capo.

I'm sure supply & demand plays its role, of course. It's not like we're looking at a catalog of 2000 VNs old and new, with millions of people lining up to purchase them.. but I think it's a genre where quality > quantity matters much more than with (mechanical) games you can play 'til you get bored and move on to the next one. I mean nobody wants to start reading a (visual, interactive or not) book only to get bored 35% of the way in and move on to the next equally boring book that just looks a little different?

Starmaker: Gonna turn it on the head: it's because they're interactive books. I preordered the physical edition of Bloodstained for $60 in real dollars and I'm currently stuck on the first boss (fucking camera!). Fata Morgana cost me the regional equivalent of $15 and I got 45 hours out of it. It's a continuous stream of original content.

Starmaker: Well Hatoful Boyfriend is on here, thanks to Devolver. Capcom I think is being a dick regarding regional pricing (if nothing else) with Phoenix Wright. The other best ones are all published by Spike Chunsoft, and GOG doesn't seem to have an in with Japanese publishers.

Firsthand recommendations:
Hatoful Boyfriend - liquid awesome, excellent translation, fat bird
Monster Prom - replayable CYOA, Western, funny
Fata Morgana - shit overall story, great music
Kindred Spirits - lesbian schoolgirl romance
Memory's Dogma - ok story, high production values
Cinders - Western, short, replayable
Fault - pretty but claw-your-eyes-out dumb at times, girly, ok story
Fairy Bell - good, with occasional leaks of idiocy from Fault

Secondhand recommendations:
Higurashi - I only played 1 and thought it pointless, but the recommendation comes from the 21st century equivalent of Norman Borlaug so there
Eden - some uwu grill thing

GameRager: I also play Hidden Object games and think some prices for some are outrageous(20 bucks for premium editions on some sites for some very short games).

clarry: Well, moneygrab editions are moneygrab editions regardless of the genre.. as long as there are people willing to shell out, some companies will keep making these.

DarthSisu: Nothing extra. So far I've been reading it completely vanilla, the way it happens to be in the GOG version.

I am using the upgraded character sprites that are the default in the GOG version, but nothing outside of what comes installed with the game.

Fonzer: Well it is your choice, but i found it better with the voice and graphic patches. Reasons you can have the same upgraded sprites that GOG has. The voice patch hearing keiichi voice is truly awesome and the graphic patch adds a few CG graphic scenes and the old sprites get changed to ps2 or ps3 graphics sprites with lip synch.
Didn't really care about that lip synch change since i preffered the new graphic sprites over the changed ones.
Anyway if you will be interested in it you would have to restart the game from the beginning if you add the mod..

clarry: Hmm, I hadn't paid attention to this one in the past. But now that I look at the voice cast & visuals, it seems quite worthy. Now I'm on the edge! Because I'm not too keen on buying episodic titles when only the first part has been released (years ago) and there's no sign of the next one..

Starmaker: ...

clarry: Aye, sounds good. Thank you for taking the time to share your thoughts on it. I might actually buy it.

AlienMind: book is way more interactive than picture-slideshow tho

MarkoH01: Could you explain this? Both are a bit different because VNs have added music and pics but how on earth is a book way more interactive? Maybe you can do something with a book which I did not know about so it would be great if you could enlighten me. So far all I did was reading lines and turning pages ....

AlienMind: well, in a typical book there are words and not pictures. thus you can interpret them however you want (see: poetry) and have your own picture in your head and not the fixed one from the artist. also, you have the thing in your hand, thus you feel the book which already an interaction.
tl/dr: games without choices is like buying a ferrari without letting it roar.