Well if it's implemented as a 'national service' kind of thing, like it is in Singapore and to my knowledge Finland and Malaysia as well, it gives you a nice reserve pool to draw from quickly, and as was done in the Second World War in Britain at least, prevent people in 'priority' occupations from joining. Everything else you can fold into the military, really.
I like to think that spaceships are so retarded expensive that there aren't many of them, because it makes for better missions sometimes.
But hey, whatever works for your campaign
Yeah, it's really hard to judge space craft cost in a universe that ignores most of the rules of physics. Thing is that doesn't mean there aren't a hell of a lot of them. The GTVA is, plain and simple, ****ing huge.
Well, if you think about it, as far as we know, the majority of combat takes place in space, between fighters and ships, rather than on the ground between infantry forces. Although I do recall mentions of marines somewhere in the campaign. I think that if fighters and bombers are going to form the bulk of Alliance spending, that they would invest in cheaper and easier to mass produce ships and technology, with a few exceptions, like the Erinyes and the Ursa.
Britain's M.O. during the Battle of Britain is probably a good one to look at, they were producing something like over 1k aircraft a month and combat was all air to air, for the most part.
Or Alpha 1 gets all the goodies and fleet support, where as everyone else duct tapes their consoles and flies mackie style. Who knows
I reckon it's likely that that kind of stuff would be a lot more widespread among the Alliance. As well as the general circle-through-square hole/one size fits all mentality when you outfit a force of that size. It's a shame you don't hear about the ill-fitting uniforms, poor tasting food, and cramped accommodation that people in that situation go through more often.