Ron Guth:
When looking at all of the P-Mint Half Eagles from the 1840s, the 1845 is one of the most common. The Top 5, in order, are 1842, 1841, 1849, 1844, and 1840. The most populous dates are 1847 (which is over twice as common as the 1845) and 1843, followed by the 1845. The point of this exercise is simply to show that if a collectors is looking for an affordable date from the 1840s, then the 1845 is a good choice -- though there are some dates from branch mints that are even more common.
In Mint State, the 1845 is moderately scarce. Unfortunately, most Mint State 1845 Half Eagles are baggy or lackluster, adding big premiums to Choice examples. The best examples top out at MS64.