This workshop is organised jointly with the AGILE 2016 conference and so the fees and registration are linked to the conference. You can either attend the conference and the workshop or just the workshop, but in either case, please, register via the AGILE registration website.
Here is the information on fees. Early registration is open until 22 April 2016.
If you are not sure if your institution is a member of AGILE (and you are subsequently eligible for subsidised conference fees), you can find the list of AGILE members here. Note that membership is at departmental (and not university) level, so e.g. in some cases the Department of Geography is a member, but the Department of Mathematics is not.