The Rarer Peace Dollars

I recently bought 1921, 1928, 1934-s and a 1924-S Peace dollars for $510. The 1928 was in AU condition as was the 1924-S. The others were in EF condition. So my collection is complete. I even have a graded 1926 in AU 58. That was so much easier than collecting the Liberty Walkers. I paid more for getting 1921 and 1921-D and 1938-D and they were just in VG condition. The early years for Liberty Standing quarters and Liberty Walkers are mostly awful expensive beyond fine condition and rare in my limited experience. Any suggestions on what would be a good next coin to collect? I lean towards Franklin half dollars. They are at least 50 years old and 90% silver. They are not making anymore of them.