I just score that today for 80 euros, it is 540x600x20 mm,I am planning to cut it and make the z axis plate out of it.I will use my bandsaw and then my router to make the templates out of plywood and after that I will use the same tools to cut this Ali,as Joe Harris has already done very successfully I must say!!!.
Click image for larger version. 

Name:	aluminium plate.jpg 
Views:	282 
Size:	64.6 KB 
ID:	23264