The letterbox grill you should be able to pick up for about 40 dollars, non genuine, but you'll have to pay to get it painted most ways you go about it. Unless your fortunate enough to find somebody that has the same colour as you that is getting rid of it.
The sticker kit for 80 dollars, not a chance in hell- is that just for the center garnish? I paid 40 dollars for my sticker and I thought that was too much. Do you have the taillights already? If you don't have the taillights then I wouldn't bother with the center piece yet. But if you do have the taillights, take one of them out and take it, along with your center garnish into a sign writer. Tell him you want your center garnish painted in gloss black - then tell him you want the lines carried across. You can either go all the way across or you can leave the gaps and try and find the CALAIS badge for the middle (good luck with the badge if you do though)
As for the boot carpet, it'd vary, if you got some second hand you'd be paying hardly anything, if you went to bunnings and got a few bits of it and did it yourself, you'd be paying hardly anything. If you went to an auto retrimmer and enquired- you'd be paying more than what you could get it done for, but being an auto trimmer, you'd have no doubts about the quality of the work.
As for calais parts, this is what I think a fair price is.
Calais Side Skirts: 100
Calais Door Moulds: 150
Calais Pop ups: 500
Calais Taillights (non gen.) 80
Calais Seats Ser 1 2-300.
Calais Seats Ser 2 300.
Calais Eyebrows for the boot 40each from Holden, no more.
Calais Center Strip above the boot. 100.
Calais Honeycomb grill 40
Letterbox grill 40
Anything else?