Have come to this thread late so don't know if its been answered but:-
1. Defending this claim doesn't cost £3k. You're looking at about £500 for your solicitors and about £500 for the brief for Counsel. With VAT and bits 'n bobs about £1500 in total. The hearing won't be more than an hour evening with sentencing. Criminal work pays peanuts for solicitors no way in a million years will it cost £3,000 even with defence costs.
2. You're looking at a mandatory 3-9 points. Probably 6-9 points + fine if you have a good statement in mitigation - explain that you're contrite, that you're sorry, silly thing to do etc. Mag will probably deliberately scare you at the start of pre-sentencing.
If you committed the defence, you'd be foolish to try and defend it - if you're found guilty, you'll get no sympathy from the magistrate in terms of sentencing.