I've been looking at getting myself a little PLC to muck around with at home, with the view to doing some home automation stuff.
Now we all know that you can really "spend the rent money" when it comes to stuff like PLC's, I've installed heaps of them over the years.
However, I happened upon a review of a mini-PLC on YouTube (that I will link to below), it is the Barth STG-600, it has 20 I/O, will operate on 7-32VDC, it's made for harsh environments and as far as cost goes, it is nowhere near the cost of a normal PLC of the same architecture.
But, the beauty of this particular device, is this, you don't have to know ladder logic or learn a new complex programming language, it uses a block based interface on a PC/laptop where you design what you want the inputs and outputs to do and then download to the PLC via a USB cable.
Check this out:Martin Lorton review of the STG-600