Hi there and welcome
$500 - with all due respects, that is on the light side, but short of auctioning your kids on Ebay you might not be able to avoid that.
My vote would be a Sunbeam 0480 grinder and a Breville Cafe Roma (you can cut the extra bottom out of the basket to render it unpressurised and therefore better.) It comes with a scoop/tamper which is not great but better than nothing.
Those two machines should be around $370.
On the other hand, if you save up for a while you should be able to pick up a Sunbeam combo (480 + EM 6910) on special for around $700.