Taking chances with a primitive translation could cause enormous legal problems for the company. And your potential client will definitely start listening when you start talking about liabilities. If your potential client hasn't already bought software, and doesn't need to translate non-culturally sensitive materials in bulk, emphasize that the company will save far more money in the long run by hiring a good translator from the beginning. Whether the translator uses software or not, this will be cheaper than buying software and paying a proofreader to clean up after it. If the client buys software and hires a proofreader for cleanup, it will essentially be paying twice for something that should only be a one-time process.
Good translators edit and proofread as they go, which is far more efficient and cost-effective.
Many a business has regretted the day it made that decision. Entire books have been written about the hilarious, embarrassing, and potentially explosive mistranslations that have occurred when someone with no translation experience and a couple of years' worth of study of the target language is hired for even the smallest and simplest of jobs. But they can also cause ruffled feathers, a spoiled business deal, political chaos, or worse - especially if the company wants to translate culturally sensitive materials, as discussed earlier. Even when in-house employees have a native knowledge of the target language, there is no guarantee that the translation will read naturally in the target language, or be faithful to the original text while taking cultural and linguistic nuances into account. This is extremely difficult work, even when dealing with relatively short text.