They aren't cheap, but they have several advantages over mine:
They are magnetised.
You can obtain them with offset holes so that your figures do not appear too regimented.
The holes are approx 27mm, so unlike mine will hold figures based on 2p coins. Plus, as long as the coins were minted after c1992, then they will automatically stick to the magmetised tray. This is because copper reached a price around this time that the 2p coin became worth more than it's face value, and from then on they were minted with a steel core and copper surface.