Grapes
This item is one hell of risk/reward in my opinion. This one of the retired non-advent calender food. All of the other old food has inflated aswell some upwards to 10k+. This will follow the same trend. I would stock up since they are still very cheap. This is already retired in will only continue to grow over time. There is a chance this may inflate quicker if their wasn't so much stupidity among the sellers (see pic problem pic). I theorized that they would inflate at 2k they are now hovering 4k-ish. Profit over time = 100% quick profit= 50-50
What inflation is looking like:

The problem (stupid crap like this):

Advent calender books
A quick profit is highly unlikely with these. But a trend has followed with these books that is only natural the older the book(lowest supply) the more expensive it is (see pic below). Time = money.

Advent calender stamps
All have inflated as well. I had 1000 copies of year 5 stamp at 7k a piece. It is now 30k a piece. The same logic applys to stamp as it does to books with the exception that stamps to inflate higher and quicker. Over time profit
Space 51 books
Very big risk/reward. " Space Exploration Guide" is currently running cheap and it may follow a trend like "the first decade". Its not retired but in theory it may be.
Mysterious valentine
Saw this tip from a certain member of the forums. It looks like solid investment but since its already expensive you must have a ton of NP to invest if you want to make seriously sick profit.
More to come later


