FMI—To convert from the projected number of tests in a given period to the projected revenue for that period, you have to make an assumption about the proportion of tests that are reimbursed. (You can see my assumptions for 2015-2016 in #msg-105563008.)
I bought today as well. I can tell you that it was not easy picking up shares. The ask kept moving away.
I also took a starter position, last week when it was in the mid-to-high 18's with decent volume. I finally gave up on my customary limit orders: I was getting 10-share fills before the ask moved up!
Just bit the bullet and bought at market, paid a bit more but avoided the aggravation. Under $19 average was my goal and I accomplished that.