If you're looking used,with that budget,your son should be able to find some very nice bookshelve speakers. Enjoy the hunt!
Recommended speaker for second system
My son´s apartment system needs an upgrade , He is using sunfire HRs speakers and I would like to give him a better choice . The amplifier he is using is the Marantz PM 7000N Integrated Amplifier . What will be your recommendation for a good speaker pair under $1200, ( bookshelf ) Regards