Caporegime
I used to squat using an olympic bench as my 'squat rack'. Worked quite well as I was just the right height for the hooks.
Walking back and forth with weight is a bit of a pain though. It is of course quite dangerous to have no catches, no spotter and no safety floor. Also boosting 140KG off an olympic bench and walking back with it is quite tricky and tiring in itself.
You might find you can pick up an olympic bench on the cheap, cheaper than a new squat rack. It won't be adjustable but could always pop it on breeze blocks if you've longer legs/torso. Just an idea
Also while I remember there's an article somewhere where somebody made a powercage out of scaffolding which worked very well and was very cheap. I think another member here made some dipping bars in a similar fashion.
How does that work? The bench being used as a rack?
I know a friend who has said he may help me make a rack if I pay him...but to be honest I'd rather something a bit more 'professional', or at least on something that has been tested with a maximum weight