Need Advice on 500$ Non-gamer PC

Hello. I am getting some funds from a company which is planning on buying some PCs for our university (mainly for us, professors, for working in our offices). The estimated budged is around 500-550$. I am going to be using it for working with office programs mostly, maybe surfing the internet and no gaming at all. I do not need speakers, keyboard, monitor, mouse or an OS just the PC itself. We are from Bulgaria and we are not entirely sure just yet which the company who will be buying is the parts is and where are they getting them from. I am not going to overclock it and I don't think I need a good video card, since from what I've read for an office PC you don't need to have one. Thanks.