Well done but e must educate a bit the buyers with such offers, not only counter offer but also explain (whenever possible) why their offer is unacceptable.
Some nice info which should be for everybody who can advertise their hacks:
Companies which use domain hacks :
Apple (itun.es), Google (no_url_shorteners, ro.me, kro.me), Microsoft (so.cl, bi.ng), Facebook (instagr.am), Yahoo! (me.me, flic.kr), Zynga (zyn.ga), Netflix (movi.es), TIME Magazine (ti.me), Huffington Post (huffpo.st), NY Times (nyt.ms), LA Times (lat.ms), CSPAN (cs.pn), NPR (n.pr), Bill Gates (b-gat.es), Wordpress's founder Matt Mullenweg (ma.tt, nav.al, ...), Digg's founder Kevin Rose (kevinro.se, mi.lk)
Biggest public domain hack sales :
LOCAL.LY sold to Infor fofr $100,000
E.CO sold to Domain Capital for $81,000
T.AG sold to Kinetic Fin for $60,000
SOCI.AL sold for $50,000
INSTANT.LY sold to Webtigo for $32,000
FAMO.US sold to Famous Industries, Inc. for $25,000
MA.DE sold to surefive for $25,000
REP.LY sold to Social Media Ltd. for $22,050
WHI.CH sold to Which.Co.Uk for $21,840
ANSWE.RS sold to Answers.com for $20,000
LOVE.LY sold to Quotidian Ventures for $20,000
DAI.LY sold to Dailymotion for $17,000
FIR.ST sold to SocialFlow for $15,000
Though Domain Capital doesn't own E.co for sure.
Note that this is not written by me but it's good to know for everyone.