Is $10,000 to replace crawl space vapor barrier a fair price?

I live in Knoxville, TN, near Lake Loudon. I'm experiencing a persistent, pungent, acrid, and nasty odor coming from my crawl space that fills the house. My house is new construction, completed in 2020, and the crawl space is well sealed with spray foam and a plastic moisture barrier. The odor appears at random times, seemingly without a pattern related to weather or humidity. A crawl space professional suggested the odor might be due to off-gassing from the plastic vapor barrier and quoted $10,000 to replace it, but I don't believe this is the cause, as it's not the classic 'cat pee' smell. I have already tried a dehumidifier in the crawl space, an iWave air ionizer, and a Shark air purifier, and am considering a UV treatment device, but nothing has helped. The odor is unpredictable and becomes very strong when the house is closed up. I am seeking advice or success stories on how to eliminate or mitigate this odor.