The IRS doesn't directly address the question you ask. They state that if you don't have an Applicable Financial Statement (AFS), which most small business don't, "you may use the safe harbor to deduct amounts up to $2,500 per invoice or item (as substantiated by invoice)." Tangible Property Regulations - Frequently Asked Questions
Since the IRS does not say you can't separate the two expenses, my advice is to go ahead and enter the two expenses separately.
