Under final Capitalization and Repairs regulations, a self-employed taxpayer may elect to apply a de minimis safe harbor to amounts he or she paid to acquire or produce tangible property to the extent such amounts are deducted by him or her for financial accounting purposes or in keeping his or her books and records. For taxable years beginning on or after January 1, 2016, the Internal Revenue Service increased the de minimis safe harbor threshold to what amount per invoice or item for self-employed taxpayers without applicable financial statements?