It's a good domain. 10 years old. Must have been a private sale. The highest priced similar domain to date was about 10k.
Here are reported sales of similar domains for the past 10 years:
agentapp.com 454 USD 2018-04-12 NameJet
agentresearch.com 470 USD 2018-04-04 DropCatch
agentmessenger.com 110 USD 2017-12-18
GoDaddy
agentseo.com 233 USD 2017-12-05
GoDaddy
agentd.com 215 USD 2017-08-29
GoDaddy
agentlegal.com 3,009 USD 2017-07-12 Uniregistry
agentoftheyear.com 4,000 USD 2017-06-18 Uniregistry
agentai.com 904 USD 2017-04-02
GoDaddy
agentc.com 1,000 USD 2017-03-12
GoDaddy
agentmagazine.com 10,000 USD 2017-02-19 Uniregistry
agentacademy.com 7,500 USD 2017-01-30 Uniregistry
agenttrust.com 7,000 USD 2017-01-28 Uniregistry
agentsystems.com 298 USD 2017-01-05 NameJet
agentvideo.com 775 USD 2016-12-09
GoDaddy
agentwatch.com 193 USD 2016-10-14
GoDaddy
agentworld.com 1,075 USD 2016-10-08
GoDaddy
agentview.com 655 USD 2016-09-19 NameJet
agentcloud.com 6,100 USD 2016-08-21 GoDaddy
agentcrm.com 511 USD 2016-08-17 NameJet
agentsolutions.com 261 USD 2016-05-10 NameJet
agentreals.com 200 USD 2016-03-22 NameJet
agentshare.com 117 USD 2016-01-17
GoDaddy
agentprint.com 4,000 USD 2016-01-06 Sedo
agenteducation.com 1,977 USD 2015-11-17 Sedo
agentreferred.com 1,500 USD 2015-06-08 BuyDomains
agentsdelivered.com 1,028 USD 2015-04-17
GoDaddy
agentia.com 1,527 USD 2015-03-08
GoDaddy
agentinterview.com 105 USD 2014-10-02
GoDaddy
agentparadise.com 293 USD 2014-08-02
GoDaddy
agentcoach.com 2,000 USD 2013-08-19 Afternic
agentzone.com 141 USD 2013-05-24 NameJet
agentwatch.com 1,300 USD 2013-04-15 Afternic
agentlove.com 3,088 USD 2013-02-17 Afternic
agentsnet.com 2,000 USD 2012-12-30 Afternic
agent503.com 166 USD 2012-11-23
GoDaddy
agentfire.com 1,500 USD 2012-07-30 Afternic
agentauto.com 2,688 USD 2012-06-06 Afternic
agentsoft.com 3,500 USD 2012-02-22 Afternic
agentmarketing.com 2,500 USD 2012-01-18 Afternic
agentgreen.com 2,250 USD 2011-04-20 Sedo
agentesaduanales.com 750 USD 2011-03-09 Sedo
agentstudio.com 2,500 USD 2011-03-06 Sedo
agentprofiles.com 1,500 USD 2011-02-19 Sedo
agentia.com 1,700 USD 2011-02-01 Sedo
agentofchange.com 5,000 USD 2010-12-29 Afternic
agentry.com 512 USD 2009-12-06 NameJet
agentgolf.com 2,488 USD 2009-10-14 Afternic
agentlist.com 180 USD 2008-12-21 NameJet
agentjournal.com 688 USD 2008-11-04 Afternic
agentinc.com 3,788 USD 2008-08-12 Afternic
Of course, none of this means much if you want more and a buyer will pay more.
Best of luck
P.S. You might post it in the appraisal section. You'll probably get more feedback there.