Final answer:
Contracts with a fixed fee are preferred by buyers due to the financial predictability they offer, shielding them from unexpected costs if the seller's estimates are incorrect. Inflation-adjusted contracts guard against changes in purchasing power, benefiting both sellers and buyers.
Step-by-step explanation:
The question refers to the type of contracts that lay a fixed fee for work completed, regardless of the seller's initial estimates. Such contracts are often favored by buyers because they provide financial predictability and protection from cost overruns. Conversely, contracts with automatic adjustments for inflation protect both parties by adapting the real price paid in accordance with changes in purchasing power. This mechanism ensures that sellers do not receive too little if inflation is higher than expected and buyers do not pay too much if inflation is lower than expected, hence, setting a real price rather than just a nominal one.