FI 800 vs FI 1000

Potion of Greater Discovery gives a Find Item buff of level 800. It is relatively cheap. At the time of writing this blog, the lowest is going for 44,000 gold buy-now price.
Potion of Supreme Luck gives the same buff, but level 1000. Its can be found in the Special section of Auction House. The items are bounded and you cannot resell them. The minimum bid is 24,000 gold but bidding often go above 200,000 gold or even more during events.

But what is the Find Item buff? The description says :

+0.1% per point increase of creatures current drop rate.

So the FI 800 potion gives 80% increase of creatures current drop rate.
The FI 1000 potion gives 100% increase of creatures current drop rate.

Let's say the drop rate is X, then FI 800 will increase it to 1.8 X, while FI 1000 will increase it to 2.0 X. Therefore, the FI 800 drop rate is only 10% less than FI 1000 and not 20% like some thought it to be.

In scavenging, that 10% can still matter a lot. If you are spending 2 mil, that 10% amounts to 200k, and you should break even if you have to pay 200k more (ie, 244k) for the FI 1000. And if you are hard core and spend 10 mil, your break-even will be 1 mil for the FI 1000 potion.