Final answer:
Generally, the rule of thumb for laboratory pricing is cost recovery pricing, where all costs related to service provision are included to ensure sustainability and potentially competitive pricing to match market rates.
Step-by-step explanation:
The general rule of thumb for pricing laboratory services is most commonly cost recovery pricing. This approach ensures that all the costs associated with providing the service, including both direct costs such as labor and materials, and indirect costs or overheads such as facility maintenance and utilities, are covered in the price charged to customers. Competitive pricing might also be a consideration, where prices are set in accordance with what competitors are charging to ensure competitiveness in the market, while still ensuring costs are covered. It is not advisable to pursue options like ignoring overhead costs or random pricing, as these methods do not ensure that the laboratory covers its expenses and can be financially sustainable.