What is an interesting gold coin date (not early gold) whose die state could be studied by a common

Longacre

Does anyone know of a date of a US gold coin (excluding early gold) that can be researched and analyzed by a common collector, but not one that will break the bank? For example, the 1851-O quarter eagle has a repunched 51 in the date. I owned two pieces, which I determined (on a very un-educated basis) to be of a very similar die state, and I sold one off. This seems like an interesting date to focus on, but other than the repunched date, I am not sure how interesting this coin is. Are there other dates that would be more interesting?

Cladiator

I had an 1882 Half Eagle once that had several die cracks, both obverse and reverse. That date is just about as cheap as you can get for the Liberty Half Eagles so it should be pretty easy to amass several of them to study die state.

kcnovice

Not sure if this would fit the request but, I had a 1903 G$1 mckinley com. coin that had a very interesting die crack and some other late die characteristics. Although not one I was interested in collecting, the coin was very interesting and I wondered about die states with this issue.