Set WF status to complete and Trigger a new WF when net value is changed

HI WF gurus

We have a requirement , where if the WF is "In-process" and the net value of the credit/Debit memo changes then we have to start over the approval process. we need 4 approvals at max depending on the $ value . for example the WF item is at Approver 3 and some one changes the price one the line item via VA02 ,in this case we have to kill or complete the existing WF and start a new WF.

Please let me know if we have any other options to  handle this situation of changing price in the midway of the approval process

Thanks

PM