1) Go to http://www.carsensor.net.
2) In the search field, copy in レグナム (Legnum) or ステージア (Stagea). (Or go nuts here if you want)
3) Hit
4) You will be presented with a search results screen, with lists of categories. Choose the most obvous (in the middle where it is white. It should have a lot of results and will most likely have a next to it.
5) You will see the category results. The "▼価格(万円)" Is the price column; translating to "Price (ten thousand Yen)".
Hope that helps.