Lower tools are what $50? Add that into the budget and good to have on hand regardless and will last forever.

I'll give that to you though, however, If your gun may see combat i'd argue you should assemble it yourself or if anything the lower to understand what is going on. You should bring it to a range and test fire to ensure working order a minimum of a thousand rounds if it may see combat. I'd hope op wasn't planning buying a gun, not practicing with it and just bringing it to a potentially hostile scenario. Your gun will be useless if if shits out and you have no idea what is going on.

Imo understanding the tool is just as important as using it.

I see your argument, just giving an alternative thought process.