Add to this the cost of the equipment to make the dam thing. You will need light boxes, developer, and etching tanks, and that does not include the cost of the chemicals. Also add in the cost of the drill and bits. You result will also not be tin plated either unless you spend even more. The end result is while it might be more expensive to get one made, you don't have the cost of capital deployed required to make one. So you are going to have to do lots of PCB's to make it viable anyway.
I have made PCB's in the past, but today even though I have all the kit I would just order one up. Maybe it is because I have more disposable income than in the past, but the difference between a DIY board and a properly made one makes getting a professionally made one a no brainer in my view. The other thing is that once you go down that route you open up your options. Want a three layer board with a ground plane for example, no problem, try that DIY.
All that said I have a notion that a laser cutting/engraving machine could be used to make single sided PCB's to a high standard in a one stop process. Basically etch the copper away and "drill" the holes with the laser. You could probably do something similar with one of those cheap milling machine things as well.