The most useful comparison is not simply oil versus cream. It is bottle, aerosol, tube, tub, bar or lotion, because the format affects how you use it and how easy it is to compare value.
Shave gels, such as the Gillette Sensitive Skin and Fusion examples, are usually sold by volume and are easy to compare on price per ml. Foams, such as Nivea Sensitive Shaving Foam 200ml, are also straightforward to compare by ml, although the way you dispense them can affect how long they last in real use.
Shaving soaps, such as Friendly Soap Natural Shaving Orange and Lavender 95g, are better compared by price per g rather than price per ml. They may also appeal to shoppers who prefer a solid format, but you should check whether you need a shaving brush or bowl to use them in your preferred way.
Pre-shave oils and lotions are often smaller-format purchases. That does not automatically make them poor value, but it does mean you should compare them differently from a 200ml foam or gel. Look at how many drops, pumps or applications you expect to use, not just the bottle size.