I purchased a license for 1 card on Apr. 10 for the price of 35 XPM. I ran the miner with the recommended settings of 1150/1500 and Catalyst 13.9 on my Gigabyte OC R9 280X until Apr. 17. During that time I found 3 10-chains and 0 blocks. Difficulty was about 10.6 when I began.
How many 10-chains were expected during this period?If your mining was running 7 days at the mentioned rate then the expected number of chains is about 10. If you got 3 then you were quite unlucky... not more than that, sorry.
Sometimes we had problems with reported blocks (stale or orphan) and such issue could be a reason for additional investigation because it can relate to some specific settings. But number of 10-chains below the reported CPD is out of the scope because reported CPD is calculated basing on the number of shorter chains and the ratio is standard (there is simple math there that has been verified on many GPUs). We even show a bit smaller value than real estimated CPD.
As for the price reduction - we did it when the difficulty reached 10.7.