The reason launching microsats is affordable is because they are piggybacking on someone else's rocket. The delta cost to launch a microsat on a rocket someone already paid full freight for is essentially zero.
There aren't any rockets going to the moon, much less another planet, that they can piggyback on... so, yes, they could send 1000 to orbit the moon, but you would have to pay full freight on the rocket. Ouch.
HOWEVER, upper-stages to move satellites to GTO are ejected out of earth orbit (for safety reasons - you don't want it to add to the space junk problem). These ejected stages are taken through an Earth-Moon Lagrange point, before being navigated on a low-energy path to a heliocentric orbit. There's no reason a microsat can't hitch a ride on an upper stage, and then wait until the ejected stage reaches the L-point before deploying itself, at which point it's downhill to anywhere in cislunar space.
Even if you were launching only microsats (without any other payload), I'm not sure the cost per satelite would be that high? Wikipedia (http://en.wikipedia.org/wiki/Comparison_of_orbital_launch_sy...) says the cheapest option right now is $2200/kg for LEO, so about $200 for a 100g phone. I guess going to the moon is about 10x more, but that's still not unreasonable...
You don't buy payload space by the kilogram. You buy it by the rocket, with the smallest launches costing millions of USD each. That per-kilogram figure is just the number that comes out when you divide the launch cost by the maximum theoretical payload capacity.
There aren't any rockets going to the moon, much less another planet, that they can piggyback on... so, yes, they could send 1000 to orbit the moon, but you would have to pay full freight on the rocket. Ouch.