Doing "Sets" Of Coins Without Key Dates?

I wouldn't not start a collection due to key dates. If you like the series then just collect what you can and enjoy them. I like Mercury dimes but just because the 16-D is out of my price range doesn't mean I can't enjoy the 95% of the other coins.

You modern collectors have it easy. There's medieval stuff I need for a set that won't show up on the market in my lifetime, regardless of how much money I have to spend.

I still have a Lincoln set missing that one key, and while I could save up for it, I've chosen to deploy the capital elsewhere. It doesn't detract from my set, which has many common, mid-grade pieces contributed from both sides of my family. Besides, I'd never fill the '55 DDO hole anyway, since it's only a variety.

I always wanted to pursue half dimes (I even bought a Dansco!), but that one key rarity wouldn't stop me.

Collecting is about more than filling someone else's holes. (Okay, that came out wrong. It's about more than filling perceived voids in a list based on what someone else considers worthy of a set.) How many Morgan collectors have all the varieties? How many consider "completion" to be whatever someone at Dansco or Whitman deemed worthy many decades ago? Don't let someone else tell you what a "set" or "complete" means. Set your own rules, your own standards -- then strive to achieve them!

This has been an invigorating conversation!