Hi Gengis,
I was where you are now about 2 months ago and came to the same conclusion;
Can't afford FF and want to upgrade ...
IMO the A500 and 550 don't cut it, why have our masters left this void???
For the right price I would consider an A700.
I couldn't find a new one but I found a s/h one with an old Minolta 28-105 and 2x4 gig cards for $800au, the a850s and 900s are $2800 and $3700au give or take.
Since then I've seen a700s new (old stock) for $1200 and as little as $800 refurbished by Sony with 3 month warranty, seems alot cheaper than UK anyway good luck with your decision but if you choose to get an a700 you won't regret it I love mine.
Mark