Go to tire rack dot com and do a search on how to check your tires. In general a car dealership sells cars and thing to put on cars. Any thing they are putting on a car comes at an extra cost if the factory does not build (or sub contract the building) the item. Your much better off buying tires from a tire store or tire rack.
As for your tires if you do not check the tire pressures regularly, I could see them waring out fast. Some of the newer cars have tire pressure monitoring systems (TPMS). But many of the systems use the ABS sensors to check pressure by comparing the diameter of the tire. If your on board TPMS system does not give you a pressure it is likely the system uses the already in place computer and parts already associated with the antilock brakes.