I think you are underestimating China's and the PLA's financial constraints.
That's right, US's high unemployment rates, and under-employment rates under the Obama administration have cut this nations buying power in half on the local level, particularly here in Central Obamastan. We have a largely agricultural economy here in Central Obamastan, and while farm productivity is up, so are the very large expenses of putting in and harvesting the crop.
As well a large percentage of the Chicago area subsist on govt programs for minor children, food stamps and medic-aid... that is a drag on the whole state, which is by and large socialist in the Chicago area, and conservative in the central and downstate area.
Illinois, Obama's home state for the decades prior to his becoming president,,, has continued to lose money, lose influence, and with our tremendously hi taxes drive away business!
As Zaphd reminded us, we must protect our industrial base, Boeing is across the river in St. Louis, still building F-18s and F-15's, so managing to maintain an industrial base and two or more defense contractors is increasing difficult, with the very difficult world markets??
So the Chinese Flankers may even find some buyers if offered outside of the country, and just as China has purchase those Russian SU-35s we will be seeing shortly if the initial order of 24 are delivered?? on time?? and will more be purchased, or are they just a momentary expediency to increase available front line fighters.
To be honest we haven't seen the evidence of a dramatic increase in the J-20 production?? will we??? I'm guessing yes, but there are indeed some serious financial constraints.
In any regard, the J-11D will likely be receiving lots of attention in the meantime, Flankers are very practical high end fighters,, their procurement will allow China to increase its defense posture and standing in the world in general.