No. Not even close. £20k might buy you the 3/4's of the piles and ring beam if you are lucky.Would the pile driven foundations have been any cheaper?
We did a test dig about a month prior. There was 1.5m of made up ground on the site (an old dairy) . I thought it manageable with a 3 tonne machine, one we removed the oversite material. The risk of trench collapse was high. Fortunately, we didn't have a spot of rain whilst doing the excavations and pour.

