I am still in the extremely early stages of learning to grade so bare with me, but with what I've read about "market grading", is it still a good practice to use already graded coins as a reference? Again excuse my ignorance.
Howdy and welcome. I would strongly advise that you pick up a copy of the ANA Grading Guide and use this extensively to learn about grading circulated coins. Additionally, if you can find a first edition copy of the PCGS Coin Grading and Counterfeit Detection guide then buy that, too, and use it quite often. However, it is also quite useful to look at already certified MS and PR coins, but I would lean heavily on PCGS and NGC for this.
I'm not sure I understand your question. The TPG's have always use market grading when evaluating coins. Do you mean gradeflation where you typed "market grading"?
