Antonio, define "affordable." It can mean something different to each of us. Also, while you're at it, define your usage pattern -- you only mention "espresso," and nothing about steaming milk for a cappuccino or latte.
I know nothing about the Nemox Napoletana, but I've come to trust Jim Schulman's recommendations, so I would indeed take a serious look at this machine. FWIW, it "sounds" good when reading the specs on the website, but that's all I know about it, so take that with the proverbial grain of salt. Also, I'm personally somewhat cautious about machines that have a built-in grinder -- if one thing breaks, you're out two machines. That said, $469 for a new machine
and a grinder is pretty hard to beat. You can always call Jim Piccinich at 1st-Line; he is a very reliable, trustworthy vendor in my experience, and he's never steered me wrong.
Sticking with new equipment, another possibility to consider for an espresso machine is the
Le'Lit PL041 ($299 on sale); this could be paired with the
Le'Lit PL053 Grinder ($269 on sale) for a very workable combination.