Re: EU friends apparantly
I think the GPS III block satellites were estimated at $500 million each, not including launch costs. (They're expected to go up on Falcon 9's for something like $90 million each, starting in the next year or two.) The 1990s ones were about 10% of that, so if you're willing to not have the latest and greatest tech you could probably build one cheaper. You'll need about 30 of them, plus spares, so try to negotiate a bulk discount. Mind the replacement costs; estimated lifespan is 7.5 years for current builds, and the record so far is 10, so you'll have to pony up cash for new ones on a regular basis. Also keep in mind you can't just throw them up there and forget about them, you'll need a ground station network to keep tabs on them, do software updates, and make adjustments as necessary.