The whole pay as you play thing is a bit of a misnomer as you have to be a salaried player for the contract to be approved so he'd have to be put on a basic wage . The fact that he was talking to Lille you'd imagine they'd offered him a 'decent' wage so what maybe £10-15k a week flat plus playing incentives, expenses & bonuses ? You could easily be up around £75k a month before he's kicked a ball so it's not exactly 'free'.
I've heard 'rumours' were after him for ages but nothing of any real substance so it might just be the latest groundless 'Owen' rumour.