Good-quality pruning tools, such as secateurs (shears), have replaceable parts that cost only a fraction of what a new pair would. If a part gives out, don't discard the whole tool. When nicks and dents in the blades become so severe that they can't be honed away, replace the blades.
Unscrew the pivot bolt and nut assembly, remove the lock, and pop off the old blade. Clean all the parts with solvent, and lubricate them lightly with WD-40. When reassembling the shears, gently push on the new blade to snap it into place.
It's also a good idea to replace the spring between the handles every year or two, to keep the tool flexible.