Wow Exciting !
We didnt go too crazy with the upgrades. We made a structual change early on increasing the living space out and then included a grand alfresco. For colour selection mainly went with what was included, we upgraded toilets, added a sink to island etc. Given electical was around 10k, I'd probably say spent around 20-25k on upgrade at the colour selections stage.
How long did you guys have to wait to get final contract price delivered from signing validation plans ?