Onus
Titan
I too favor lower budgets.
Another option would be for Paul to build a budget box. Don then gets $n00 to upgrade that, and Thomas gets an additional $n00 for another upgrade; see how that plays out. Each upgrader can keep or scrap any existing part. Optionally, if they scrap something, they can consider it "sold" for 50% of its price, and add that amount to their upgrade budgets.
Another option would be for Paul to build a budget box. Don then gets $n00 to upgrade that, and Thomas gets an additional $n00 for another upgrade; see how that plays out. Each upgrader can keep or scrap any existing part. Optionally, if they scrap something, they can consider it "sold" for 50% of its price, and add that amount to their upgrade budgets.