Staining black

Many years ago I fitted out a shop in pine that we did a white finish by mixing white undercoat and turps, applied by rags, followed up with estapol. Looked great.



Now my wife wants a bookcase stained up in black to match something from Ikea, and so I googled about and it was all Prooftint etc, expensive spirit based stains with reducers etc etc. Got out from the shed a can of black satin oil-based paint, mixed some in a tin with turps and ragged it on a scrap bit of pine, two coats. Looks great.



So what am I missing by not buying these ready made tints/stains? I know 'my' method cost nothing and the tints cost a lot, but what do they give me that the free method doesn't?

thanks

John