count, print out and delete rows that do not contain a digit
You could try this:
import pandas as pd
df = pd.pd.DataFrame(dict_you_provided)
print(df[df["AskingPrice"].astype(str).str.contains(pat="[a-zA-Z]", regex=True)])
# Output
URL OfferedSince DateOfSale AskingPrice ... BuildYear TypeOfHouse Garden Garden-yes-no
68020 URL OfferedSince DateOfSale AsingPrice ... BuildYear TypeOfHouse Garden Garden-yes-no