We did this in an office where we were stuck with 1 port in each room, and we put a 100Mb switch in each room. It was OK for basic tasks, web surfing, email, etc - but the BIG downside is that if you start doing heavy network traffic (for example, copying a multi-gig file from one office to another) you chew up ALL the bandwidth for two offices, because each office is sharing a single uplink.
So it really depends on your level of activity, but you may have a larger issue with a contractor taking you for a ride (depending on your definition of "exorbitant"). Yes it should and will be more expensive multiple lines if you want them all in different locations, but if you want to run say, 4 lines into one location within the room then the extra costs should be:
- More expensive cabling cost (usually pretty nominal, maybe $0.50/meter)
- More expensive wall socket (Maybe twice the price of a single)
- More expensive labour costs for crimping the ends (they can take a while, and includes the time taken to get a cable tester onto each end)
- Larger or multiple patch panels in the central location
What you've got to weigh up against the cost of the installation is the cost of configuring, maintaining and purchasing multiple switches cascading off eachother. If I had a choice I would have paid the extra money to get it done properly (multiple lines into the room) because the hassle of maintaing THAT MANY cascaded switches can become prohibitive.