I can see a great attraction in having the 'proper thing' if it is to be used a lot, but for a general diy er like me who does some turning, a bit of plumbing, some box making, a bit of bookshelf making, a bit of car fixing, bit of sculpture .... well, you can't justify the cost of proper things for everything. There is also satisfaction in making "something from nothing".
I saw John's post when it first appeared and its on my to do list. The one from JEC is a nice job too. I have some birch left from the frame of a very old small IKEA sofa, cushion bits went to tip, frame got sawn into manageable bits. Some has been used, plenty left for free jaws
It also occurred to me that you could buy a cheap workmate-alike, typically £20 or so from the usual places, use the threaded parts, nuts and the handles and be left with a spare trestle.
And it's only just occurred to me that the next time a pair of shoes wears out they might not go in the bin - leather vice pads beckon if I can get usefully large slices - probabaly only for the small vice, but maybe if my wife parts with some old tall style leather boots when the soles are beyond repair I could repurpose those.