Jaime Hernandez:
Around 1937 Lincoln Cents were produced in much better quality than in previous years. This lasted until about 1944 as circulation strike Lincoln Cents from 1935 to 1944 from any mint can be found in really nice gem condition much easier than other dates in the series.
Therefore, the 1937-P Lincoln Cent is very common in circulated grades. In Uncirculated condition it is still very easily obtainable at a small premium. In MS66 it becomes worth a larger premium but just about any collector can own an example. In MS67 condition there are hundreds of examples known and can be purchased inexpensively compared to many other coins in the series. There is even one known example in MS68 with none being higher.