Cheapest way to do new driveway and dropped kerb

The cheapest is gravel. I would suggest you excavate to 230mm. Lay 150mm of scalping compacted in two layers with some additional scalping where the pavement meets you drive to create an entrance. You can then lay approximately 30mm of gravel. The advantage of this method is at a later date you can remove the gravel and you will have a base ready for block paving.

gravel will be the best option for you id say but only when you have a driveway of some sort installed only then you can apply to have your kerb dropped and the council are big on waste water it must stay within your curtilage/property boundary so drainage is a must if you follow my advice you will not need to apply for planning for the driveway but you will for the drop kerd