Constructive criticism:  I believe it is a bad idea to hold a sale on friday.

The GPU's are already on sale practically, they are low enough that anyone looking on the market for a GPU who knows how to buy GPUCoin and knows about the store will likely buy them regardless whether they are at the current price or discounted further.

The problem is not that the prices are not cheap enough.
The problem is twofold:  1.  People don't know about the GPUCoin store in general.
                                 2.  The process of getting GPUCoins is too confusing and labor-intensive.

By holding a sale you are not likely to increase your customer base (you will a little).

What might happen though is people who were going to buy (I was going to buy but waiting for the coin to go back up in price) are now going to wait until the sale.

What you should have done is spent the money you are going to lose through selling the items cheaper on advertising.

You also NEED to make it clearer how to get GPUCoins and stop scaring away potential customers.  I have not looked for awhile but the last time I looked your site and business had serious problems.  There was no link to a page telling a customer how to get GPUCoins.