Don't buy new! Check out other brands on eBay. Lots of Cat(erpillar) and other (better) brands than River Island, and lots of boots that have been worn once or twice before the owner realised they were the wrong size or whatever.
I got a bargainous Ash pair on eBay recently, they currently retail for over £200 but the seller said they didn't fit her....I picked them up for £50 and I luffs them muchly. Buying nearly-new means someone else breaks them in for you too!
Don't focus so much on the brand, search eBay for brown boots and who knows what you might find?!
Pic on my profile. I put in a bid on Ebay for this pair of second-hand River Island boots, but didn't win. They eventually sold for almost £70! I would love a new or second-hand pair like this, but can't find them on any of the shops/websites I've tried.
Has anyone seen anything similar? Calf-length, tan leather, low heel? for anyone who finds me a pair