Yep, you can link each image on your website to the PhotoDeck back-end and use it only as an e-commerce cart.
The nice thing is that you can fully customize the pricing structure (i.e. the options), and there is no commission on sales.
The minus is that it doesn't have an automated script to put on your website like fotomoto, so there's a bit more manual work. But you can also use PhotoDeck as the front end to host the galleries, the design is fully customizable.