conked out and wont tick over, oil bubbling

was driving a long the other day and the car had lost power about 3 times in the journey, i had manage to get it started again each time but on the way home the engine went all rattly for about 30 seconds and then i lost all power, i could see steam coming from under the bonnet and when i lifted it there was oil absolutely everywhere. the car would not tick over at all and just made a single 'click' noise when the ignition was turned on. RAC towed me home and simply said it does not look good at all, it also has a leaky radiator but i was topping up with water regularly. if a ball park price of fix could be included in answer if anyone else has had similar iissues that would be excellent as she might not be getting fixed again. thank you very much in advance