Cool topic. For 10 years my system sat the same, and I was happy with it. Then I discovered the boards here, and at other sites...
I have bought a used Bolder DIO, then the Bolder PS for the DIO, then some Bolder M-80's, then had the DIO upgraded to Mensa (OK, that was actually a transaction for something "new" I guess), a couple of Bolder digital cables, a Monarchy DIP Superdrive, a Nakamichi CD4 to use as a transport, a B&K pre/pro, a passive PS Audio pre, ALL this year.
Most of it was Agon and here, and in spite of the shipping costs to Canada, I have made out well, met some great people, received some great advice, and made some significant improvements to my system.
I recommend buying used, once you have lurked around here long enough, to get to know some people, or ask some people for help and opinions on gear, and sellers.
Thanks to all that have assisted me in this!