The logline positions the inheritance as the inciting event, but it's really the first instance of a possessed doll attacking...
The Sessions (2012)
The above is what I would use to pitch the script. As far as a logline for developing the script:
After his marriage proposal is rejected, a 38 year old polio victim confined to an iron lung, a devout Catholic, hires a sex surrogate so he can lose his virginity.
I would re write it so it reads as having more intent. For example:
After his girlfriend rejects his marriage proposal, a devout Catholic polio victim confined to an iron lung, must hire a prostitute so he can lose his virginity.