وفقاً للأسعار المرساة في المنافسة غير محدد الكمية = provide items at the prices determined during the bidding process without specifying a particular quantity.

"وفقاً لـ" means "according to" or "in accordance with."
"الأسعار المرساة في المنافسة" refers to "the prices determined in the competition" or "the prices set in the bidding process."
"غير محدد الكمية" means "quantity unspecified" or "without specifying a quantity."
So, when combined, this phrase conveys that the supplier, upon being awarded the contract, agrees to present the items at the prices determined during the bidding process without specifying a particular quantity. In other words, they are willing to provide these items at the agreed-upon prices as needed, without a fixed quantity being specified.