OK, I was going to say a lot, but it gets into IRS and audit rates and quickly I start violating my own posting rules and I'll have to delete my own post!
This just isn't a subject that gets me wound up. But then again, I am a fastidious recordkeeper and I can easily pull up when and what I paid for almost anything. I keep receipts and owners manuals for significant purchases and even small purchases where warranties are involved.
What this situation has caused me to do is to have separate personal and business PayPal accounts so there's no intermingling of transactions.