The magnet itself would be low on my list of probable problems (unless it has overheated).

Run through the mist test in diagnostics and see what you get. Problems with the long opto can make it look like the magnet is now working.

When you lift the playfield there is a board on the upper left and the connector will often get pulled off the board. Check that.

http://pinballrehab.com/1-articles/solid-state-repair/game-specific-toys/200-mist-multiball

It should be repairable and all the parts available. There's one part (a choke on the opto board) that is slightly hard to find, but it is available. There is an IC on the opto board that is no longer available, but you can get a reproduction opto board (if that's the problem).

The article I posted earlier will help you troubleshoot the problem if you get the game.

If it's in good cosmetic shape I'd go for it.

I think for a game that is not working and has bad cabinet art, which is not available by the way, that's high. According to Pinside the game should be 1,700 to 2,000. So far this year five Drac's have sold on eBay for an average of 1,550.

If you have to replace the opto board it's about $84 (AUS) plus shipping, so figure $100.

On the other hand a working Drac in good cosmetic shape would be over 2,000 in SoCal.