So in summary:
20% of your investment went into capitalising the asset you now hold
80% of your investment went into capitalising a private company in which you didn't get any shares
Like I say, that's just my understanding of the current equity balance of the ICO. I'm happy to be corrected if wrong.
I think the 20/80 rules only apply to the last 147K ETH that poured into the ICO that was above their intended 250K ETH cap. So I think the correct way to look at it is that (250+0.2*147)/397 = 70% of your donation went into capitalizing an asset you now hold. The remaining 30% went to an unplanned, "ex post facto" fund whose assets you now have no claim over. For the next 2 years this new fund will purchase tokens (at a price that gives zero profit to the public sellers) and give those tokens back to the Bancor Network that issued them.
Bancor blog clearly states that 20% of raised ETH goes into reserve, which is ~80K. They crowd sold only 50% of BNT (~40M), the other 40M they gave to themselves. In the end, 80M of BNT is backed by 80K of ETH. At a price of 100 BNT per 1 ETH this means 10% reserve ratio.
People, at lest learn times table before you invest into something.
OK, let me zero in a little more considering your logic. They intended to take in 250K ETH, they ended up with 397K ETH. As you say, 20% of all ETH goes into reserve so we've got three pots now. In rounded numbers, (a) 0.2 * 397 = 79K ETH for the reserve; (b) 0.8 * 250 = 200K that actually "paid for" 39M BNT distributed to the public; and (c) 0.8 * (397-250) = 118K ETH that goes into an unexpected "post ex facto" fund to buy back public tokens at ICO price and give them to Bancor Network.
So the proportion of your donation that actually bought BNT tokens
for your own wallet was 200 / 397 = 50.4%. The other 49.6% of your donation went to buy tokens
for the Bancor Network - some now in the reserve pool, the rest over the next 2 years during buyback.
Final approximate ICO cost for a single purchased BNT token assuming $400 per ETH is thus 200,000 *400 / 39,000,000 = $2.05 per BNT.
Bancor's loss of control on how and when to stop the ICO resulted in the percent of your donation actually purchasing tokens FOR YOU slip from the
promised 80% to an
actual 50.4%.
Not a very well run ICO.
The math is spot on, and it matters a lot. Now the bancor foundation will control almost half of their own currency. I don't trust that people who were looking for roughly 20M and raised an extra 55M of self-controlled funds over night is going to do the right thing. If it was initially stated that only half of the funds would be distributed to the investors, would you have bought in?