Hi mate, I'd recommend looking on ebay/pistonheads/autotrader etc and get a feel for what things are going for. The 'completed listings' option on ebay helps but I'd say most cars on there are sold outside of ebay anyway to avoid fees among other things. People don't generally buy cars of this age at auction without viewing them first.

For reference i recently paid just under 5k for a G plate 2WD Saph with Tax & Mot. Looked nice on the surface but turned out to be pretty rotten but that's another story! Also bought a very clean rolling shell complete with interior and trim for 2k recently.

Don't be fooled into thinking the shiny ones are mint, most have had a hard life. If you want to shift them quickly they will need to be priced well otherwise be prepared to hold on for a while for the right buyer. Also be prepared to have loads of silly offers when you advertise and expect anyone serious to give the cars a good going over.

Cheers

Brad