I'm a serial bike buyer having bought 58 bikes in 43 years (someday someone will find a cure - death or being penniless not withstanding) and like to think I know a little about wasting money!
For the last 15 years or so I've owned 10 Harleys and a Buell. HD riders like to think their bikes are depreciation proof. Many of them pay huge prices, and may get fair trade in prices, but ignore the thousands spent on accessories whose value is never considered, certainly by dealers. Two of my Harleys have been bought with around 1000 miles on the clock and I've put 25,000 miles on both in two years and actually made a profit on sale. New prices had shot up, which helped, and this was an exception, as I won't add up what these bikes have cost me as its too frightening.
With Japanese bikes I think the only sensible approach if depreciation concerns you is to buy cheap and sell cheap. New bikes lose more than the 20% vat as soon as they leave the showroom, so the hit is massive. The other mistake I've made several times is to buy with the heart and not with the head, but then again bikes are part of my DNA, so there's no hope!
Another problem I've seen is the ridiculous number of people who buy the wrong bike for them, and re-sell quickly or leave the bike languishing in the garage. The V-Strom is nearly immune from some of the issues above as its so practical, user friendly and competent, while being a great ride and economical in the wider sense, that its nothing short of superb.
Getting caught out with dealer discounts/offers is always one to watch for - no doubt you'll not be caught again. When considering how much you've lost in depreciation (which only takes effect if and when you sell of course) take a look at the world of Harley Davidson and you'll feel better. Ninety five pound an hour labour, astronomical spares prices let alone the initial purchase price. When someone counters with the "low depreciation" argument, you can now see through it.
Ride your bike, enjoy it, spread the depreciation over a few years of ownership and things don't seem too bad.
Sorry to prattle on, but I'm on holiday in France and the portable stress relief device (aka the wife) doesn't do mornings and I'm bored!