That's why I don't buy new, or almost never. With new stuff I buy it, I try it, I get bored, I sell it, I lose money. Call me crazy, but I hate to lose money. With used stuff I buy it, I try it, I sell it and I break even or lose/gain a little. SOOO much better.
The other reason I love used is that I don't have to cry over the first ding or scratch. It's a sickening feeling to put a blemish on a perfect bike or kayak, but if they guy before you did it already a new boo boo is no biggie.
With bikes, at least, I have settled down a bit. After owning and riding 36 different bikes and swapping steeds at least every season for ten years I know exactly what I want and what fits my size and style. The thing is it really took until mid-life with lot's of trial and error to figure it out. If I had done that at full retail I would be selling pencils in a can by the Art Museum - AND I wouldn't have been married for 15 years.
It can be a challenge to find what you want on the used market but if you are vigilant and patient almost everything comes up for sale sooner or later. The musical stylings of Ebay and Craigslist have changed the world.
If you have already dated around and you know which kayak or bike you want to settle down with then you might buy new. Otherwise save your money and save the natural resources by picking up pre-loved and recycled model.