I don't want to be stepping on toes, but stainless steel screws are not as strong as 12.9 alloy steel.

You can easily look up the specs online typical stainless tensile strength -100-120,000psi (the specs on SS list a range, not a given number). Grade 12.9 alloy steel tensile strength is 175,000psi.

When I got back into rc from a long absence, I came to hate those phillips headed wood screw things that rtrs used to always come with. I bought several SS kits and got rid of those things. Taking stuff apart to upgrade and maintain, I was running into heads that were rounding out using my Thorp drivers after 5 or 6 cycles. I don't have that problem with 12.9 grade fastners.

The prices look pretty close to me if you compare kits for the same rc, the numbers of screws looks similar too. I do like the box idea, but its not a deal maker given the other differences.