Proof 1852 Large Cents are exceedingly rare. Researchers and experts have uncovered only three examples, all of the Newcomb 24 variety. It should be noted that some 1852 Newcom 8's have been called Proofs in the past, but these have been debunked by modern researchers being merely Prooflike examples.
The three Proof 1852 Large Cents include a PCGS PR64BN, a PCGS PR65RB, and a PCGS PR65RD. On all three of these Proofs, either the obverse or reverse dies are off-center -- on two examples, the off-center obverse caused a raised rim to appear from 5 o'clock to roughly 10 o'clock.
The Proof 1852 is a recognized rarity in the series. The most valuable example is the PCGS PR65RD that sold for $105,750 in July 2015.