A GPS running watch is one of those purchases that quietly lasts five years or quietly annoys you for two. The job is simple: tell you how far, how fast, and where to turn, so training stops being guesswork. Buy it once, buy it well, and it disappears into the routine.
Most brands refresh their line every September or October, so last year's model is usually 25 to 40 percent off between March and May. That spring marathon window is when the previous generation drops to roughly $450, which is the sweet spot we'll work with.
One honest catch: the 18 months of no interest is a deadline, not a discount. If a balance is still sitting on the card when that window closes, retroactive interest gets added to whatever's left. Pay it off a month early and you never have to think about that.