Please read my edit: If the army really did engineering cheaper, then we'd contract them out for money. Since we're not doing that, it's unlikely that they're more cost-effective than hiring a professional construction firm.
You really do not know what a combat engineer is about, do you? They do not construct water piping. Nor power plants. They are not full engineers. They build roads. Chop trees. Make airfields. Field works. Stuff that is cheap to make. Hiring a construction firm for roads, airfields, and other such things when you have fully capable and trained men, with more specialised equipment for doing these tasks more cheaply, is stupid.
You really think it's cheaper to deploy full military than to hire a contractor? The amount of outsourcing the army does would state otherwise.
Please state where I said we were going to deploy 50,000+ men for foreign aid?
Army dudes don't travel singular. But i never said 50,000. Even individually they're more expensive - for what you get - than a specialist construction company.
Go out and hire a professional engineer if they are so cheap. No? Can't afford them? It's like the difference between a builder and a plumber/electrician. Sure, electricity and water sure is nice, but an actual house is what we need.
Please state where I said we were going to deploy 50,000+ men for foreign aid?
Wasn't... Wasn't the very premise of this argument that you think we need more men for foreign aid? Isn't that the very corner stone of your point?
See before, defence from future conflict, and blowing illegal immigrants out of the water.