Welcome to the forum..
With a soft floor, you get extra storage that will be handy with a young one....with an older model hard floor (which is where you are budget wise), storage is where you are likely to miss out.
Both weight wise should be fine.
Soft floors aren't that bad setting up...you just need to have a routine, and alter your trips. Eg..for your trip to Tassie, rather than moving every day, you go to one spot for a couple of days, and do daily trips out and about....and then move onto next spot for couple of days...
For that budget, I'd suggest you are more likely to get a younger soft floor than hard floor, which being your first camper, means it maybe in better condition ?
Hard floors "generally" are easier to setup......