I bought my first donor on May 4th, 2019, and bought the second donor on August 17th, 2019. I ordered stage 1 on September 3rd, 2019, and took delivery of it on November 9th, 2019. I ordered stages 2 and 3 on April 29th, 2020, and received them via freight on June 5th, 2020.
That's a long way of saying, order at your own pace. As others have said, as long as DF is making parts, you can order them.