Is it worth buying leather oil/cleaner on a Prius?

I have my own detailing business. I can assure you that treating the leather is better than not treating it at all. Oil and cleaner are two separate things. A leather cleaner will remove stains that can't really be seen on dark leather such as the colour dye in jeans and other much. An oil will make the leather more supple and protect it. Try and get hold of a nourishing balm instead of using oil I find it more usable and gives better results

Here's a photo of a Mercedes SLK I detailed recently the first pic is a before photo and the second is after the leather had been treated with a cleaner and a nourishing balm. I left it to cure for half an hour then gently buffed it off. It brought back a deep colour to the leather...







I normally treat my leather once during a spring/summer detail and then again when I prep the car for a winter detail.

Ps: the quality of leather really varies, even with more premium brands. For instance some of the leather on some Audi's is terrible, it starts to wear on the bolsters far too quickly for the price tag! (This is only my opinion of course!)