Hey Linda,
I know this part of Logan City fairly well after buying 2 units in the area in 2006 following thorough research.
I bought a 2 bed unit for $122,000 in Jan 2006 and sold it October 2007 for $201,000. Most of the units/townhouses in this area were built in early 1990s.
The rent had been $140/week but I got $180/week on the first day of ownership. Rents have increased and you could get $220 plus now, but with prices for these units at $220K or more, the yield is down to 5%.
In my opinion, I think this market has peaked so I would be weary about buying in now - I think the party has passed. Considering the same unit I bought was only $70,000 in 2003!
The other unit I had was a 3 bedroom in central Logan which was $140,000 (Dec2006) renting for $200. Now this would be $220K renting for $240/week - again the yield has decreased and investors will soon abandon this area for some time (in my opinion).
Most of the other areas I have been hunting for cheapies have all gone up in the same timeframe (Elizabeth north of Adelaide, Cairns and Beenleigh/Eagleby).
I am now hunting in Sydney....
Good luck with your search
cheers
Michael