The Draper crimper is only £18 and I would probably have cause to use it more than once.

The problem with the Halfords leads are: a) they are a bit weedy and b) they are only M8. The starter mounting bolt is at least M10 so we're looking at a custom cable.

Digging around in my bookmarks I found ECS (Electrical Car Services). They can make up leads to order; in this case a 45cm long tinned copper cable with insulation and a right-angle M10 ring terminal and an M8 straight ring terminal is £14.28.

E.g. ECS Custom Cable

Pretty good value I think.