Final answer:
In a House race, a party committee can spend up to $2.4 million on average, while for a Senate race, the average cost reaches $27.2 million. However, there is an additional limit of $51,200 that a national party committee and its Senatorial campaign committee can contribute per campaign to each Senate candidate.
Step-by-step explanation:
In a House race, a party committee can spend up to $2.4 million on average, according to 2020 data. For a Senate race, the average cost reaches $27.2 million. Additionally, a national party committee and its Senatorial campaign committee may contribute up to $51,200 combined per campaign to each Senate candidate.