There are 6.1B coins now with another 6.1B vesting over 3 years and another 8B or so for mining which will take many years
So if there are 7 or 8B in circulation in 6 months, $1 would be a $7 or $8B cap or roughly the current cap of IOTA.
Maybe this is not insane with some good marketing and hitting those roadmap milestones, or maybe it is and we should just end it all now
$10 is probably a pipe dream but I could see $1 happening in a bull market with a successful mainnet release, dapps announced, etc.