I believe the piggy bank offers, in random order, these items:

Achilles Heel
A. Tears
A. Lyre
A. Arrow
Black Orchid
Bonus Pack
Chronos timer
Croesus Fortune (?)
Fertility Wand
Helios Ray
Hypnos Blanket
Medusa's Blood
Morpheus Arms
Nyx Pack
Pandora's Box
P. Stroke
Poseidon's Pack
Water of Youth
Zeus Lightning Bolt

when you fill your piqqy bank you are offered a couple black market items that you can buy for equus rather than passes. you can see what is currently offered on the piggy bank page

i don't know if everyone gets the same items at the same time (i doubt it) but as an example i just filled mine today and can get water of youth or pandora's box for equus and my next offer is zeus lightning bolt and philotes stroke

Yes, when Piggy "pops," everyone is offered the same BMI items.

The piggy bank offers a select number of items, at fixed prices.
There appears to be some sort of pattern to which items it offers. I've been tracking it for a few months (early this year? late last year? I don't remember exactly) and it seems to have a set roster of items that it cycles through, and just switches out one or two items in each cycle.

I've tracked it for 3 full rounds. We're currently on the 4th round. Here's all the items that have been offered for the past 3 rounds in the piggy bank:
-Morpheus Arms = 299 000e
-Artemis Arrow = 39 000e
+Water of Youth = 99 000e
+Pandora's Box = 109 000e
-Zeus Lightning Bolt = 139 000e
-Helios Ray = 99 000e (2nd Round had Apollo's Lyre?) (3rd Round: Philotes' Stroke)
+Poseidon's Pack = 179 000e (2nd Round had Hera's Pack?)
+Bonus Pack = 99 000e
-Hera's Pack = 309 000e (2nd Round had Nyx Pack?) (3rd Round had Fertility Wand.)
-Apollo's Lyre = 19 000e (2nd Round had Achilles' Heel?)
+Philotes' Stroke = 59 000e (3rd Round had Black Orchid.)
+Repeated Poseidon's Pack
-Chronos Timer = 199 000e
-Repeated Helios Ray
+Piece of Cloud = 119 000e
+Hypnos Blanket = 29 000e
-Aphrodite's Tears = 159 000e
-Achilles' Heel = 89 000e (2nd Round had Black Orchid?) (3rd Round had Helios Ray.)
+Nyx Pack = 859 000e
+Medusa's Blood = 89 000e
-Fertility Wand = 109 000e (3rd had Chronos Timer.)
-Black Orchid = 89 000e (2nd Round had Apollo's Lyre?)

Based on that, I'd expect a Bonus Pack and probably either a Poseidon's Pack or Hera's Pack to be queued up next, after the Bolt and Stroke.

Thank you so much to all �