I have: YYJ Fiesta, YYJ xcon, YYF DV888, Shinwoo Loop, Yomega Brain, duncan top, and a lot of extras. I am going to sell them in a begginers bundle. How much is this stuff worth?
Assuming near flawless condition:
Fiesta XX: $15
XCon PRO(key): $35
dv888" $25. Yes, I know I am biased against the dv888, but honestly this model doesn’t hold BST value as there are a ton of them. $20 is not unusual even mint in mint box unopened.
Loop $3-5
Brain: $3-5
Duncan Top: $4-6
Ideally, not a great beginner’s bundle. It sounds like you’re just trying to unload some stuff. That’s fine too. XCon is NOT a beginner yoyo, nor is the dv888, NOR is the Fiesta XX(but it is beginner friendly). The top will just be an off-topic distraction, the Brain will be abandoned after 2 weeks and the Loop will be lost in a corner.
Part it out.
http://blog.mainstreethost.com/wp-content/uploads/2012/08/Dr.-Evil-One-Million-Dollars.png
Had to be done.
lol
Yes i am trying to get rid of this stuff. Although its not a good a beginners kit it does let someone explore a lot of different styles of play.
X-Con: Missing side caps, minor dings
DV888: Dings, scuffs, and scratches
Fiesta: near mint, in box
top: 
Loop: good condition
Brain: good condition
Extras include: string ~100, lube thick&thin, bearing removal tool, counter weights, 10ball bearing, another bearing, extra response pads, ~2 dozen collector cards, signed Boulay card, YYX stickers, shims.
Your XCon just got knocked to $20-30 due to damage and missing caps.
Your dv888 is at $20 now due to damage
The extras all combined add to $10
It’s not good to have beginners explore too much. It lends to confusion. Intermediate exploration pack? Very likely.
You’re better parting it out and using the “extras” as deal sweeteners.
I would say $15+ for the extras.
100 string- $10 cheapest
2 lubes- $5 each, could be 2 for $5
CW-cards-stickers-shims- $5
A 10 ball- $10 cheapest
Another bearing, eh, $3
And a bearing remover. $3
So, more than $10 studio42!
You should give
Them to me for free 
lol