Hi Praveen,
First, it's actually a very bad idea to store mat_price in the member property. Using some value stored in the property you have to work with a long and slow FOR/NEXT loop. Please, define some additional account member and store mat_price in it. Then the code will be simple and fast.
B.R. Vadim
P.S. In BPC MS it's possible to use FLD to get a property value in the REC, but for BPC NW this function is missing.