Coffee nerds of Raleigh, I need you

I’ve got a specific question and don’t know where to start. I’ve decided to focus my attention on putting my wife’s espresso machine through the paces and really dialing in my home espresso-making skills. I’m a total noob to espresso and have a fairly unrefined palate for coffee in general. I imagine I’ll go through a bit of coffee working out the various kinks in the process, and I’m expecting to do a lot of my testing in the evenings (mornings are hectic with a toddler).

So here’s the question: any local recommendations for an affordable, moderate quality decaf bean for espresso?