Here you go. Boat Point search criteria, 34 to 42 feet, $30k to $80k, Australia wide you have 171 to choose from.
http://www.boatpoint.com.au/boats-for-sale/results.aspx?base=1456&vertical=Boat&eapi=2&N=0%200%20607%20610%201586%201587%201599%201588%201454%201595&silo=Stock&Range=Price:30000,80000|LengthFeet:34,42~1&sort=~Price&Page=1
Of those 61 are in Queensland and 5 are in WA.
www.boatpoint.com.au/boats-for-sale/results.aspx?base=604%20896&base=1456&eapi=2&silo=Stock&sort=default&sort=~Price&N=0%200%20607%20610%201586%201587%201599%201588%201454%201595+83&vertical=Boat&Range=Price:Min,Max&Range=Price:30000,80000%7CLengthFeet:34,42~1The first boat, the Alan Payne Koonya at $30,000 might fit the bill accommodation wise but hoisting the main will be an effort. Later IOR style yachts have higher aspect ratio main sails that can be full battened and a lot more manageable short handed if they are set up with lazy jacks and a boom bag. The IOR yachts of the 80s vintage are fin keelers and usually more head sail powered yachts and can be balanced very well and be very light on the tiller.
A great feature of the IOR style yachts is their powering to windward ability and how they will heave to. Sailing along, if you want to stop, without touching the sheets, just haul the tiller to windward (ie, gybe the yacht) and lash it hard over and the boat will stop dead in it's tracks and creep to windward at a half to one and a half knots. Very useful if somebody falls overboard.
I have always owned fin keeled sloops and I would have nothing else. Fast, predictable, easy to manage and they just look good.
The S&S 34s are a magnificent yacht as are the 39s but I doubt you will get a 39 worth owning within your budget. A 34 maybe, however for you and your tribe I think a little bit squeezy.
So what happened with you?? Children 13, 11, 8 and then 1. Did the tube tying or snipping fail??

Until recently I owned two yachts, both 34 foot long. One an S&S 34, the other a Van De Stadt 34. There is bugger all between them in performance but I sold the S&S in favour of the VDS because of the room and intelligent accommodation layout of the VDS.
Most importantly it has a stand up shower and head and that is what keeps the ladies happy. It has a double berth forward and another aft plus two settee berths with the possibility of two pilot berths.
Another contributor to the forum in WA bought an aluminium VDS 34 recently and took it on a surfing safari with 5 or 6 adults last year and he swears by it.
I just found this one below and it is new to the market. Certainly by the photos this a magnificent example of the marque. The accommodation layout is non standard but extremely well thought out and executed.
Damn, if I didn't have the one I already have, I would be buying this yacht. Look at the paint job on it!!!! It's within your budget too!!! and the owner is prepared to assist with delivery!!!!
Now I am really pinged off and I am going to bed. Shoot!!
www.boatpoint.com.au/boats-for-sale/boatdetails.aspx?R=16282023&Silo=Stock&Vertical=Boat&Ridx=4&eapi=2