Yeah, the key is to get in quick. Nothing cheap left for Ajax - all £40+ but there are some reasonable ones for Marseille still - probably because it's still a way out.
For Marseille there are some driveway spaces up off Coldean Lane for £10 - £15.
If you're mobile, so the longer walk isn't an issue, it's probably a better option as you can get away without the massive queues of the car parks...
Missed this, but with constant refreshing I managed to pick up Ajax around 9:15 and Marseille at 9:25.
Keep refreshing - the odd one does come back up for sale from abandoned baskets etc.