I am sure you know this but those Nespressos are not espresso machines at all. Basically they are a nicer k cup setup.
I have been roasting beans for many years so if you are that geeked out already a Gaggia is pretty much a great starting point. The rancio Silvia being another good line to look at.
You also need an excellent grinder and the sky is the limit. The “least” grinder that will do the proper job is a Baratza Virtuosa. I own 2 Virtuosas, both purchased used. Great mid level grinder and Baratza is a fantastic company on the support side as well.