If anyone's interested in the cost of my drive it was:
Timber: 59.40 leva
17 tons hardcore: 233.00 leva (including a total of 60 leva for 2 deliveries)
14 x sheets of steel reinforcement: 256.40 leva (including 10 leva delivery)
4 x 1mtr length drains: 96.00 leva
9 cubic mtrs Ready mix cement: 855.00 leva (95 lev per cubic..free delivery)
Total: 1,499.80 leva plus labour.
That gave us 4 inches of hardcore and 4 inches of cement.
Just got to wait 1 month now before I can drive on it!