Tire pressure monitoring

09 Silverado LTZ . Bought this with wrong wheels and tires. Looking for the sender's to make this monitor system work. Question is there any aftermarket more cost effective sensors available that work with this factory system? I find the factory ones quite costly.

I've bought Dorman and VDO sensors for my Grand Prix. Using coupon codes on Advance Auto (or whatever you might have local to you) and buying online and picking up in store (when available) I can sometimes get them for $35 each.