There are a few options for you
- Buy a cheap soap that comes in a plastic bowl/container, and either use the cheap soap and save the bowl/container, or throw out the cheap soap and put a puck of good stuff in it.
- Buy a nice soap that comes with a nice bowl and just keep reusing the bowl.
- Look at some of the more notable online shaving stores like West Coast Shaving they have a good selection of bowls for your soaps
I use options 1 and 2 myself. I bought some Wilkinson soap tried it and threw it out because I hated it. It cost less than $2 so it wasn't a big hit to the bank account, then I went out and bought some L'Occitane Cade soap and put it in the empty container. I also regularly use Proraso soap so I always have an empty container from that kicking around to use.