Defaulting to the last thing the user did is very often the simplest and best thing to do. But I'd question the initial defaults -- is 1 b.r. 1 bath the most common option? Maybe it is. Is it the most common option for people wanting their place cleaned?
For all I know you've figured this stuff out and the answer to both questions is yes.
Business reasons can in this case also effect what sane defaults are. Maybe one want to anchor the consumers thoughts by defaulting with "cleaning the whole house" and barging down, or maybe one want to start with one of the cheapest options and barging up. This is where testing really shine as one can test each default for a while and see what default brings most revenue.
For all I know you've figured this stuff out and the answer to both questions is yes.