Thanks both Gale and Tock, that concisely explains the question regarding my ledger and goes on to help me figure out the answer to the miscellaneous puzzlements I had buzzing around my head.
Out of the ordinary purchases/sales (particularly onces taking place in threads) should be put in the ledger, but payments RP'd in threads like selling another PC a pint shouldn't be added because it goes towards the daily income which I assume is after tax/upkeep/staff wages etc.
I guess I should still add tips though xD