I tried D3200, exposed at 6400, for 15 min at 21-220C, but thinned 1:5 instead of 1:4 (Do not drink and think at the same time) And the results printed on Oriental FB VC look o.k. Pictures were nightshots at a harbour and early morning trains in the other harbour.(posted 9126 days ago)Additionally I used DD-X at the same time for a roll of D400, exposed at 1600. Here the Ilford times work fine.
14 minutes at 250C seems a little steep to me, may give it a try a 9-10 min/250C. But I agree with you, Ilford times for the D3200 aren't worth a single penny.
For finer grain I would recommend Fuji Neopan 1600, btw cheaper, developed in X-Tol 1:1.
For the economy, the DD-X can be reused at least once, after the Deltas I used it for Tmax100, increasing time from 7 to 9 was a little bit too much.
Good Luck