I am another who does race, but doesn't have a power meter. I don't doubt the usefulness of powermeters, and I am well aware of the limitations of HR training, but as things stand I don't think my training or performance is limited by the lack of a PM.

Partly this is because I am experienced in HR training, I know enough to "aim off" for HR lag and cardiac drift, and so don't suffer too much from its supposed disadvantages. If your intention is simply to get fitter and faster, I'd recommend starting with a HRM and taking the time to learn how to use it. I have not yet exhausted its usefulness. I'm not ruling out buying a powermeter in the future, but there's still plentyof room for me to improve my performance without one.