This year, thank God, capes are in, swing coats are in and trapeze coats are in ( the ones shaped like triangles, like this ^). What with it being a summer of maxi dresses and waterfall cardigans still doing the rounds, along with smock top/loose dresses over leggings/jeggings, 2010 has been a good year to be up the duff in.
I got a gorgeous JoJo Maman coat on ebay for twenty quid +P&P, also a really warm US cardie-coat, so I recommend having a look on ebay for a tailored pregnancy coat in your size, or else going the high St fashion look with a cape/swing coat in a size up, so it still fits the shoulders but accommodates your bump and bigger bust. I agree that lashing out full price for a mat coat you'll only wear for a few months is a bit mad, and that the choice isn't great anyway.
As an aside, why does every retailer think pregnant women just want to wear black, grey, navy and purple during the winter? when you are likely to feel drained and sallow as it is? Matching a whole wardrobe of slightly different shades of black is a nightmare, it looks really scruffy. I would love to see more reds, clear bright blues, warm pinks, khakis, camels, chocolate stuff. Yes, I can use scarves and jewellery and stuff but it's still a bit tiresome.