this is from the package insert for procrit:

"The first evidence of a response to the three times weekly (T.I.W.) administration of PROCRIT is an increase in the reticulocyte count within 10 days, followed by increases in the red cell count, hemoglobin, and hematocrit, usually within 2-6 weeks. Because of the length of time required for erythropoiesis - several days for erythroid progenitors to mature and be released into the circulation - a clinically significant increase in hematocrit is usually not observed in less than 2 weeks and may require up to 6 weeks in some patients."

that comes out to $600/week.