Let me lay it out for you.
1. Factory Ruger receivers are cast. This is a process where molten metal is formed into a negative mould. It is cheap and fast. These receivers are noted for their generally loose tolerances, thus they are not desirable for high precision shooting applications.
2. Aftermarket receivers are usually CNC machined from billet aluminum. This material is more uniform, stronger, and lighter. By machining the receiver, the tolerances are much tighter, minimizing the margin of error in alignment of the trigger group, bolt, and barrel clamp.
3. $189 for reference, is a pittance in the gun world. High performance shooters would not be caught dead with a $200 scope on their rifles. That's why you see in the EE forums 10/22's selling between $200 and $1000+.
When you are looking at the $250 10/22's in catalogs, you are not seeing the aftermarket parts, only cheapy factory parts.
If you are genuinely interested in firearms and shooting, choose your questions more wisely. Dump the ignorant commentary that pervades your posts, and ask pointed, relavent questions. You will get a better quality of answers.
As I have said before,
"Ensure brain is in gear before engaging mouth"