Understood & agreed !
If you google them, you'll probably find them down to £50 ish sometimes & you may be lucky & find a s/h 1 for less.
You need to make sure the steel is at least 6mm thick to prevent it bending.
If you're going to make 1, the dimensions are very basic for the actual tray. It's just the width between the chassis rails less the thickness of the side brackets + a bit of leeway for fitting it (say 10mm).
The front to back dimension is the width of the winch+ approx. 25mm to allow for the bends & the nuts that will hold the fairlead.
The slot for the rope is sized to suit the fairlead hole & make sure the rope doesn't contact the edges if pulling at an angle. Slot position to suit the rope outlet from the winch with the winch centralised as much as possible (may not be totally central due if motor & gearbox lengths not the same.
Side brackets are positioned so that the height of the fairlead is as high as possible without the fairlead / rope rubbing on your bumper
( I lifted my tray at least an inch above it's "designed" position to reduce the underhang / minimise what could get hit / seen).
Front- back positioning is dictated by how close you get the winch to the radiator & where the free-spool lever is located & getting it to clear the mini cross-member that goes between the 2 sides of the body just below the grille.
I fitted my steel bumper first then optimised the winch tray brackets afterwards - as I knew it was going to be a tight fit with my ultra short FirstFour bumper
If you've got a steering guard you need to decide what your going to do with - as it will probably interfere with the winch tray & some have the mounting brackets on the inside of the chassis legs - which will reduce the space for the tray & the winch. My winch has only about 10mm spare between the extreme ends & the heads of the side bracket mounting bolt heads - makes it a bit of challenge to insert into the gap !
Paul
Paul