Abstract acrylic paint is currently being sold for just £2.00 a pouch at Hobbycraft UK. The quantity of premium quality, high pigment acrylic paint you get for your £2.00 makes it some of the best pound for pound value you can get. I'm not sure this product will remain in Hobbycraft following this promotion so - get it while you can.
My personal experience of this paint is that it is slightly thicker than the paint you get in pots, but can be watered-down and slightly thinner than acrylic paint sold in traditional artists tubes. It has great covering properties and a smooth finish. I have experimented with mixing it with other brands of acrylic paint and have had no problems. Brushes can obviously be cleaned with plain water.