Double Eagle Type Set, Proof (1850-1915)
This set has to rank as not only one of the most difficult sets to complete, but one of the most difficult to even start! The price of admission for even the most common of the coins (a Type 3 $20 Liberty) starts at around $15,000, and that would be for an impaired proof! A decent coin would start at nearly double that amount. Obviously the great "stopper" in this set is the proof Ultra High Relief. While there are several out there, they will all set you back a cool million $ or more, and consequently make completing this set a dream for most of us.
Notes:This set has bonuses. Please see the Set Composition for a listing.