I think 052D has become PLAN's Plan B for destroyers. Just in case the Type 055 and its new technologies didn't work out, they got something to fall back upon.
Previously I assumed that 052E would be 052 with 055 radars, but that is based on the assumption and grounds that the 055 has passed its trials and the new equipment has been proven. While I believe the 052E with new radars might be cheaper than an 055, whether its more cost effective is another matter. The most expensive things in the ship are the radars and sensors, the ratio of number of missiles served by the radar sets over the cost of the radar sets would be in favor of the 055 over the 052E if the 052E has upgraded radars similar to the 055. If the 052E has the same but improved radars over the 052D, or improved but lower cost radars, there might be a justification for it. But of course another factor of cost are the engines, and the 055 has double the number of gas turbines over the 052C/D/E. (The equivalent of the C/D/E would be Block I, II and III by USN parlance).
And once again, if they take out the Type 517 radar on the back, redo the hanger so its more like the 055's, the 052E can hold two helicopters, but only Z-9Cs instead of Ka-28s.
I think the number of 055s might be 6 initially, two 055s assigned to each Fleet, North, East, South, or a pair for each carrier group, one active and one in dock. This can go up to 8 or 9 if they want two 055s per battlegroup. This batch will also trial the new technologies and once they are matured, the next phase will be 055A.
If the 055 becomes more focused on the AAW role, carrier escort rather than carrier killer as Western blogs like to paint, the 052D will become more of a GP AAW/ASuW ship, leaning a bit more towards antiship combat.