I currently have 9 PMG notes and looking to expand my collection. I like to keep consistent grades when collecting a series and most of my notes are Grade 40.
The higher denominations in a series end up costing a small fortune when keeping with consistent grades. Is it a bad idea to have higher grade low denomination notes and having lower grade high denomination notes in the same series? Would it be a failed collection? Some of these notes I'm seeing are expensive and I'm wondering what the best solution should be to have a respectable collection.