The problem is the injectors will be expensive at any auto parts places locally or on-line. The GM ones go for around $90 each even at Rockauto. Aftermarket $60 and up. Reman injectors around $30-$40 each. Too bad ZZP doesn't have the stock injectors for a na SII 3800 but the prices are outstanding because they buy in bulk quantities. Plus they are flow matched in any given set.
Therefore, I would make darn sure the injectors are bad or actually need replacing.
Here is another alternative on EBay even though you would have to win the bid. Low mileage complete rail with all 6 injectors.
Click here