Hi Neethu,
Sorry I did not understand your requirement fully.
So my understanding here is ,You want to update Price and Date only when Price from file and Price in MDM are different.
This can be easily done in PI.However if you want to in MDM,you canuse 2 temporary fields.One field temp-Price and other temp-Date.(say)
If (Price1<>temp-Price,Date1fromsource) assign this to temp-Date
This will assign will check if 2 Price fields are equal,if not then it will write the value of Date 1 in the other date field.
Please come back with findings.
Thanks,
Ravi