If you want to buy a grobag for your little one, there is a special offer happening at BumpTo3 right now. If you buy 1 grobag at full price (must be 1.0 tog), you get the second for half price! There is also free delivery.
From those in stock, prices start at £25.99, meaning you can get 2 grobags for £38.99 (or £19.49 each).
P.S. This offer may be active for today only - I am not sure.