Good links there with the buyback clause from the listing on Mpex:

"2.2. The Terms of the IPO.

(a) The Directors have elected to divide BitVPS into 1`000`000 (one million) equal non-voting shares with a total equity value of 1`200 BTC (0.0012 BTC each). In the event of liquidation or breach of this Agreement they solemnly promise and warrant to repay all investors holding shares at this minimum value. The Directors through their elected representative solemnly promise and warrant never to issue more shares either on MPEX or any other venue nor in any way to dillute existing shareholders at any point in the future ;"

So it looks like 0.0012 BTC per share is the minimum BitVPS has to offer per share if they like to buy them back.

and the price structure for the first 150 000 shares looks like it was:
 
"(b) Based on the Statements of Profit and Loss published as per 2.1.b above, as well as on evaluation of market demand, future profitability and projected evolution, the Directors have elected to offer in this IPO a total of 150`000 (one hundred thousand) shares, as follows : one block of 30`000 (thirty thousand) shares at a price of 0.0022 BTC each ; one block of 75`000 (seventy-five thousand) shares at a price of 0.0024 BTC each ; one block of 45`000 (fourty-five thousand) shares at a price of 0.0026 BTC each.
(c) The Directors warrant that no further shares will be offered by them for a period of 30 days from the date these offered shares are sold. The Directors further warrant that they will never sell more than half the total shares."

If one assumes that the first 150 000 shares were sold out at there stated price then they raised 30 000 * 0.0022 + 75 000 * 0.0024 + 45 000 * 0.0026 = 66+ 180+117 = 363 BTC there and possibly 700+ btc more if the rest of the shares up to 419 306 that have been sold (accourding to outstanding shares on the link to the btct page) were at 0.0026 or higher price.