IIRC you have to change the whole inlet shaft. Not a small job as you will need to do all the timing at both ends of the engine. That is a softer rev A inlet shaft compared to the rev B shaft. I take it that this is an early AXX engine? Rev B Inlet camshaft around £300 IIRC.
Is the wear we are looking at on the "corners" of the lobe? Perhaps looking at it on phone but cant really see where the wear is.
Was your cam follower in bad shape after a short time?