Townhouse development project in Brisbane

I am looking to purchase a block of land within 7km from Brisbane CBD to build 4 to 6 townhouses as investment properties and probably sell them for a profit if the market recovered.

I am wondering whether buyers in today's market prefer to buy 2 bedroom or 3 bedroom townhouse ? s

Say 2 bedroom for 450K (100 sqm) and 3 bedroom for 500K (140sqm), is the selling price realistic in today's market ?

Any suggestions would be greatly appreciated! :)

Thank you.