The best green beans I've roasted (consistent roast, good flavor at a light roast) was a bulk dump off sale of a Guatamala blend from Genuine Origin. I think it was $1.60/lb in a 70# box. I wish I could go back in time and buy a few more boxes.
Right now I have 2 contenders: Costa Rica Heredia and and El Salvador’s Bourbon Naturale, both from the Green Coffee Company, my roasts, in a Whirley Pop to medium and prepped in either a Barista Express as a strong Americano or, using same grind and dose (20.5 gms), in an Aeropress. Yum