Would not call them dishonest since every other dealer sold items at inflated prices.
ex. there was a Megahouse Binbougami figure I really wanted. Cost $91 and almost pulled the trigger and bought it but checked online and could get it for $50.
I bought a music box from that same booth for its suggested retail of $30 so I have no idea how dealers decide what price something should be.
I think I can answer that question since I've worked many WonderCons & SDCC shows as a dealer at my friend's booth for the last 14 years...
The main reason for inflated prices are in fact Supply vs Demand. This applies to 99% of dealers as they are here to make money. This is a fulltime job for them - this is what pays their bills & feeds their families. For the Japanese toy market, it is commonly known to make ONE production run of a product. This means, no matter how popular said toy is, they will not continue to manufacture in mass quantities. (ie: Hasbro's Star Wars 3" action figures are mass produced year after year....) On rare
occasions, the Japanese toy market will reproduce models such as Yamato's Macross line (prior to Yamato going bankrupt). However it took years for Yamato to re-release the same models. I remember I bought my 1/60 scale YF-19 for $120 waaaay back then. Now, it's worth approx $250+ unopened, MINT condition box. It was eventually re-released several years later, but the packaging was different and model was re-engineered to improve the transformation from jet/gerwalk/valkrie mode. Just because there was a re-release, it didn't dampen the $250+ cost of the original.
Japanese toys that were released 5 years ago sold for fair market value such as One Piece P.O.P. series 1/2/3/etc... averaged $80-$120 depending on how much the vendor paid for his wholesale prices & import shipping costs. Now, those same figures are climbing to $200+ depending on popularity of character & limited supply.
A UFO catcher plushie base yen price to a vendor could be 650Y, however this does not include the hefty overseas shipping costs incurred for large wholesale orders (btw, cargo freight on a boat is cheaper than air)...For a vendor to make *SOME* profit, they'd have to charge about $15-$20 per plushie after everything is said & done. Keep in mind, the product needs to sell otherwise, the vendor loses money. Breaking even is not an option, otherwise vendor just spent a shit ton of money all for nothing and wasted his time & effort.
Also keep in mind, if the costs seen online is too good to be true.... it usually is. The $50 online tag could also mean it's a bootleg, damaged box, and/or they might charge a lot more for S/H costs too.
eBay = best online appraisal tool
On the subject of magazines:
They cost anywhere from 700 to 2000 yen. This doesn't
include shipping costs. Depending on total spent, the vendor has every right to price his magazine page cut outs anywhere from $5-$10. He's not selling EVERY page since there ARE written articles....I'm pretty sure he's not cutting out the 'wordy' pages just to mount & sell....
Side note: I've seen what wholesale prices are for Japanese magazines to local US book shops... Trust me, wholesale discount is pretty shitty!!