22 LR Upper - Pressure Plug?

[AndyLate]

I am going to pull the trigger (so to speak) on a barrel, bcg, and magazines to build a dedicated rimfire upper.

Is it worth the money to buy the polymer plug that fits into the receiver extention and applies forward pressure on the BCG?

The vendor I am planning to use sells a Bore Buddy reliability kit with the plug, CH insert, and springs for $26.50, which seems rather dear, considering I can buy a rimfire CH from them for $15.

Thank You

Andy

P.S. If a spare firing pin is a good thing to have, let me know please.