Material costs
Is there some info on mat prices listed somewhere? I realize these things change pretty often but I'd like to have SOME idea what to offer people if I'd like to buy or sell certain mats. I'm pretty new so I have literally no idea what things are worth.

As a very rough estimate, shards about 100-200 each, blue shards generally higher and maybe up to 300
2 star materials can run from 500-1000 from my experience, and 1 star materials probably 100-500
Various opinions are here: http://forums.spiralknights.com/en/node/2216
Life will be better if we ever get an auction house like suggested here: http://forums.spiralknights.com/en/node/2043
If an auction house is added material prices are sure to crash. Availability is currently extremely high, but because trading ingredients is inconvenient only a portion of the market is available for purchase.
An auction house would allow everyone to sell anything effortlessly and prices would come crashing down to almost nothing.
That's not to say there should never be an auction house, but if one appears it will impact the game in other ways.
I'm not sure that's an entirely bad thing. Monster bones probably shouldn't be going for 250+ crowns each.
Alternatively, instead of an auction house, it could be a trading house.

hm, I should bump that lol, I wasn't going to bump it til I got back to school and could actually sell but...*goes to bump*
Ironically, I've never seen monster bones go for 250 crowns. Heck never below 500. I was considering going for 400.
Yes, an auction house would make prices stabilize, but it wouldn't really crash when you have random people deciding value and undercutting and stuff. There's only so low you can go. If you go too low, someone else smarter will buy your item, sell it off for a better price. So yeah, go ahead and sell a monster bone for $1, I'd buy it and sell it for 1 dollar less than the next highest value.
But until then, I'm just going to buy and sell roughly based around what's in that thread or my mood :D Best thing is when you can get people to offer first :-)
Why are blue shards so much more expensive? Are they used in a lot of popular recipes or something?

I think so
http://wiki.spiralknights.com/Blue_Shard
All the basic cobalt stuff and even advanced stuff. So hey I'm probably crazy for sticking with my 100 price but its not a big deal for me. Though if I get a message in game and you offer more, I'll definitely take it :D
im in the same boat right now - im probably over paying for almost everything, but it isn't all that bad