mark, no Eisenhower dollar is rare; as a result, the coins are relatively inexpensive and a complete set may be acquired without difficulty. However, many were badly struck, without full detail, especially in 1971 and 1972, and most pieces acquired nicks, scratches or "bag marks" from contact with each other soon after striking. Although lower-grade silver coins can be melted, this is not practical for Eisenhower dollars due to the lack of precious metal content, and dealers often try to get any premium they can on face value. Completing a set of highest-grade specimens may be difficult and expensive, especially for the 1971 and 1972 from Philadelphia or Denver, which were not sold in mint sets, and thus only came to collectors through banks. A 1973-D piece, tied with ten other specimens for the finest known of that date and mint mark in near-pristine MS-67 condition sold in June 2013 for $12,925. According to numismatic writer Steve Reach, "as more people submit modern-era coins like Eisenhower dollars for third-party certification, the true rarity of many issues in top-grades is becoming clear." Some of the 1971-D pieces exhibit a variety in which (among several differences) the eagle lacks brow lines, these have been dubbed by Eisenhower dollar specialists the "Friendly Eagle Pattern". The 1972 dollar struck at Philadelphia is broken down into three varieties, which were made as Gasparro adjusted the design to take advantage of better steel being used in the Mint's dies. A midyear change in the design was announced by Brooks at the American Numismatic Association's 1972 convention in New Orleans, although she did not state exactly what was being changed. The three varieties may be differentiated by examining the depiction of the Earth on the reverse. Type I dollars show the Earth somewhat flattened, Florida pointing to the southeast, with the islands mostly to the southeast of the tip of the peninsula. The Earth is round and Florida points to the south on the Type II, with a single, large island to the southeast. The Type III is similar to the Type II, except that there are two islands directly to the south of the peninsula. The Type II is from a single reverse die, used in March 1972, and erroneously placed in service at Philadelphia—it is identical to and should have been used for the silver proof strikes at San Francisco. The Type III was placed