Check cable pricing at
www.monoprice.com first
Second, you will find that very few receivers have HDMI inputs and even less work 100% with HDMI at this time. So, while I do recommend that you run HDMI to both locations, you will still want to have component and composite video as well. Those three cables types (HDMI, Component, Composite) are the absolute minimum you should be running to any television/distributed location.
I would also include some (2) coaxial cable (RG6 Quad Shield) to the locations in case you decide to add a local cable box/sat box later on down the road. Cheap to do it now. Plus, TVs typically have built in tuners.
All cables should be CL2 or CL3 rated for in-wall use... should being the key word.
For HDMI distribution you will need both a HDMI switcher, if you have multiple sources, and a HDMI splitter. Expect to spend several hundred dollars on those items - and no guarantees of them working due to HDMI/HDCP issues.
Finally, I always suggest the people take a look at front projection if they have not done so. For the price of a decent 42" plasma you can put up a 100" projection screen. That is what home theater is all about.
Budget of course, is key here. You want to start with your total budget. Then, determine how much of it will be split among the different items. If your budget is absolutely fixed, then look about 10% under what your budget is, because new costs arrise all the time.
