It all depends on how much you want to spend, deck size, engine preference and if you are looking for a residential or commerical machine. A used commerical unit with a bagger will be hard to find and to get one new will be quite expensive.
The devil is in the details.
obstacles?
lawn size?
terrain?
exercise?
health of the operator?
quality of the task?
the future?
economics?
Now, for me
This task must be done well, no clumps, no scalping , little wasted time..
.5 acre
many flower beds, many buildings,ect
rough terrain
72 years of age
health problems
Solution??
Two mowers?
One with swivel front wheels ?
Or , the Toro 30" one on steroids...
Im looking for a residential one and probably in a range of 2k-ish.