Добрый день!
Подскажите, пожалуйста, что в SAP'е понимается под ценовыми разницами и откуда они возникают на 44 счете?

Вариантов много. Например:
http://help.sap.com/saphelp_erp2005/helpdata/ru/a8/b994d9452b11d189430000e829fbbd/frameset.htm

Price differences (PRD)
Price differences arise for materials valuated at standard price in the case of all movements and invoices with a value that differs from the standard price. Examples: goods receipts against purchase orders (if the PO price differs from the standard pricedardpreis), goods issues in respect of which an external amount is entered, invoices (if the invoice price differs from the PO price and the standard price).
Price differences can also arise in the case of materials with moving average price if there is not enough stock to cover the invoiced quantity. In the case of goods movements in the negative range, the moving average price is not changed. Instead, any price differences arising are posted to a price difference account.
Depending on the settings for the posting rules for transaction/event key PRD, it is possible to work with or without account modification. If you use account modification, the following modifications are available in the standard system:
None for goods and invoice receipts against purchase orders
PRF for goods receipts against production orders and
order settlement
PRA for goods issues and other movements
PRU for transfer postings (price differences in the case
of external amounts)

Спасибо!