Haven't really used the ridiculously old PC in the study productively for ages and its now died.
Considering a low cost replacement - generic office use, some edx/similar courses in programming (dual screen), photo management/cd burning, ideally able to process basic avchd video edits/conversions
This seems a reasonable starting point.Dell Optiplex 9020 USFF i5-4570s QC 2.9Ghz 8GB Ram 128GB SSD Win 10 Desktop PC (Buy it now $349.00)
Add ons and better suggestions much appreciated
Really solid pick that includes an SSD for that price, Optiplex is definitely the way to go. Depending on the specific programs you use(multithreaded or not) a step up to an i7 may be worthwhile, otherwise the i5 will be fine. Double check the I/O on the model you get is able to support your two monitors/cables.