Purchase Requisition picking wrong Info Record

Hello everyone,

we have 2 Purchase Info Records for a Material(different Vendors). In Info Record A is the price for 100 pieces 88 Euro. And by Info Record B is the Price for 250 pieces 185 Euro.

If a purchase requisition is by MRP created with this material for 250 pieces, the wrong info record(for 100 pieces) is picked in the purchase requisition.

Actually it should not be the info Record that has cheaper price(for 250 pieces 185 Euro) selected ?

How can we set it up without source list ?