I'd say that a grinder makes a huge amount of difference; in third place after the coffee/roast itself, and then the water used for brewing. However, there are levels to this, just like cigars. There's not much use having a $3600 Kafatek grinder unless one is drinking aged Cohiba Behike-level coffee.
The Encore is slowly being replaced by the Encore ESP. The new ESP has two major advantages: a better adjustment mechanism to allow for basic espresso grinding, and a better (tastier) set of burrs that were formerly only available on Baratza's next model up, the Virtuoso. A common modification used to be fitting the Virtuoso's burrs onto an Encore, but that mod is irrelevant now that the ESP exists. I can't say that the upgrade to the ESP is "worth" $50 extra, though - a base Encore will make a night-and-day difference from a blade grinder.
Baratza sells refurbished grinders - or at least they used to - I don't see any listed on their new website. I'd say that it is worth giving them a call to see what refurbs they have at the moment. +1-877-701-2021 weekdays 8:30am-12:00pm PST Also, Baratza's customer service has been excellent in my experience. My first grinder was a 2014 Baratza Vario (espresso grinder), and Baratza has always been helpful with parts, advice, modifications, and upgrades over the years. Breville bought Baratza in 2020, but there haven't been any noticeable changes since.
Myself, if there was no need for espresso grinding, then I wouldn't buy an Encore or Encore ESP today. Fellow is blowing out the previous generation of their Ode grinder for $169 in white and $199 in black (
https://fellowproducts.com/collections/last-chance?variant_by=sale). The Ode is a much, much better grinder than the Encore IMO, and can easily be upgraded if one gets seriously into coffee. The Ode cannot grind for espresso, though. Another option is a $200 hand grinder, but that is not for everyone - only those who want the best possible cup at the $200 price point, are willing to sacrifice ease-of-use, and are brewing cups of coffee, not pots of coffee. (Hand grinding enough coffee for a pot will test one's patience. Highly frustrating.)
Good luck!
ETA: FWIW, I'm the same "baldheadracing" on home-barista.com