3020 supports Pentium® Dual Core and Celeron® Dual Core (65W for MT & SFF, 35W for Micro).  LGA1150 socket.  Intel 4th gen. 3010 supports Pentium Dual Core and Celeron too. LGA1155 socket.  Intel 3rd gen. 390 too.  LGA1155 socket. Intel 2nd gen. [URL] [URL] [URL] not sure if these low end cpu are worth it unless the sole purpose of purchase is reverse engineering or curiosity for Dell mechanical engineering, or you want to buy as many units as possible, and you care more about the total number of units than the performance per unit. for general use i5 is best middle choice.  i3 is a bit faster than core 2 duo (i3-2100 is 30% faster than C2D E8400).  
Okay so, Since I have bought my first dell optiplex I have wanted to buy more, to reach my goal. My goal is is to buy every kind of optiplex from the 2nd - 4th gen intel dell optiplex by the end of 2022. Attached is all of the dell optiplex I want.[IMAGE] The important 'question' is that are there any cheaper alternatives? eg Celeron cpus, Pentiums etc?
Should i buy more dell optiplexs?