heres a shopping list for you....
5m x 3m x 2.743m (32c) Shed
14 packs Verticore bricks (290 x 162 x 90) (I can help you source these easily enough)
1 pack Modular 76 bricks (290 x 76 x 90) (ditto)
1 roll Bricktor
24 bags 'Brickies Grey' premixed cement (20kg bags)
3m yellow or cream brickies sand
150 galv wire ties
1250w Brick lintel
$2012
1 @ standard 820 Timber entry frame w/sill, single rebate
1 @ 2040 x 820 Solicor Flush panel door
1 @ Gainsborough Govenor entry handle
1 @ Gainsborough 850 Double Deadbolt
3 @ 100 x 75 s/steel loose pin hinges
1 @ 915mm Raven door seal
Depending on how well the gyprock butts into the frame, you may want to get some 12mm quarter round quad to trim around the door frame for neatness.
May want some skirting boards too, because the finish between the floor and the walls may be a bit rough. 67 x 19mm bullnosed MDF skirting - 4 lengths (5.4m)
$492
70 x 35 MPG10 pine - 4 @ 3.3, 4 @ 5.1 (wall plate)
170 x 45 MPG10 pine - 2 @ 3.6 (hanging beams)
90 x 35 MPG10 pine - 6 @ 5.4m (ceiling joists)
50 hanger straps
65mm x 2.8mm bullet head nails
$240
22 sheets of 2700 x 1200 soundcheck gyprock ($13.60/sheet)
Plasterboard glue
Plasterboard tape
Plasterboard nails
Plasterboard corner beads for around door reveal
60m? sound proof insulation batts (not sure of bag sizes - probably around about 10m? per bag) ($8.55/m)
5 lengths 75mm coved cornice (4.2m lengths)
$1052
you can get every thing listed above (except the bricks) at Bunnings. They will even deliver it if you send them a list.
I guess you need power points and lights too - call an electrician for that. Im sure theres one here on WF. Wasn't Chewy a sparky?
The way I have quantified it, its not really going to look very pretty from the outside, and I have also assumed a few things, like that your shed has a concrete floor (a reasonably flat one). I have allowed for ceiling insulation, but nothing on top of that, so it will be exposed. You can throw a few sheets of plywood or whatever on top of it to cover that up if need be.
Also I have allowed for rough bricks inside and out. You could spend a bit more and get face bricks for the outside if you really want.
My fairly rough estimate of material cost is $3796 (bare in mind, Im using trade rates, and theres a bit of educated guessing involved, but its close enough). Labour is what will kill you. a Brickie would probably charge $2000 for a job this size, a chippy, maybe $400 (though its so piss easy you should be able to do it yourself - I can draw up the layout for you in about 1 minute), the gyprocker will be around about $600 (something you probably shouldnt attempt yourself if you want a neat job), a chippy to do the door and (if required) skirting boards - a couple of cartons of piss should sort that out.
I think you'll get away with under $8000 complete, including electrical work.