I spent $3k on a .com last month, it was a package deal with a 2nd .com so the deal was $5k in total. I'm using these as my main projects, so I was buying as an end user not a domain seller
I had also just sold a domain for ã2.5k so in effect it cost me nothing - if you wanna think like that, and I do
p-o-k-e-r.com
c-a-s-i-n-o.com
Most I've paid for a drop was $1373 (again, as an end user) for ukchess.com - this was appraised by one guy on this forum at reg fee, I don't care 'cause for me it was within my budget and I know I'll make that back in no time once I launch the site.
As for purchases as a reseller, the most I've paid is $380.