Ruger GP-100 (either blue or stainless) in 3, 4, or 6 inch barrel length is ideal. GP-100s are probably the most reliable and durable .357 available, with excellent quality, accuracy, design simplicity, and "bank vault" ruggedness.
The other revolvers mentioned are excellent -- no question about it -- but a SHTF situation by definition demands the utmost in reliability and endurance . . . that's the GP-100's competitive forte.
In addition, GP-100s meet you price range and you can opt for the three inch barrel (better concealment), the four inch barrel (best all around utility), or the six inch barrel (increased accuracy and velocity, perfect for .357 hunting).