When adjusting a purchase in MYOB sometimes you will receive the error "The value of this purchase would leave you with 0 on hand and a non zero $ value". The following document explains why this issue occurs.
The reason you can’t alter the purchase is because when you change a purchase, there are a number of transactions taking place in your accounts including your dollar values on hand.
When you buy something the value of the purchase is held against the QTY you have in stock int he stock on hand asset acocunt.
When you sell it - with every sale the average cost $ value of goods is moved from your stock holding asset account to your cost of goods sold account.
The entire cost of goods has been allocated once the last item is sold.
If you try to change your buy price on the orginal purchase MYOB will try to allocate the $ value change to the stock code. If you have sold all the stock the dollar figure has no where to go as MYOB does not allow you to keep $ value on an item code without any QTY.
If there was at least one item remaining in stock it would lump all the dollar change into the last item in stock which can also be misleading when reporting on Sales margins.
Foreign currency variance can become available well after the goods have been recorded and sold - We normally recommend creating an item code call FX-variance and apply all the variance to this code on the purchase. The code should be linked to an expense account of a similar name.