In general, I prefer to keep things simple. I do not buy the Best Ever Fitness Gadget of the Month, even if they make a red one.
That said, sometimes I need to get fitness things to make the experience better. There are two kinds of purchases: good for the body and good for the psyche.
In the former category, I have bought, at different times, weight lifting gloves, better pedals for my spin bike, and actual workout clothes that don’t end up weighing a thousand pounds and lying there all wet on my back.
That last item also fits into the latter category. Having workout clothes that fit, feel comfortable, function well, and look cute enough to distract from the sweat factor can make the difference between feeling up to a workout and not so much. New headphones, new music, a sassy helmet (always wear a helmet when being sassy, just in case!), all good for the soul.
What small thing can make the difference today? Get it and go play!