It's hard to tell from the pictures. The description says that the vehicles are complete except for the Skystriker and Night Raider.
$150 for a complete Night Scrambler
$40 for a Skystriker missing just its chutes
$15 for the incomplete Night Raider
$50 for the Night Raven
$15 for the Triple T
$35 for the Mamba
$50 for the Tomahawk
That's $355 just in vehicles.
Then you have what appears to be a nice white Storm Shadow ($40), a complete 1986 Viper ($20), a mail away Quick Kick MISB ($10), a complete Doc ($15), and a complete Clutch ($10) and the value of the lot is probably around $450 or so.
For a collector, $300 looks like a good price for the lot - IF everything is complete as he says it is. The nice thing about Craigslist is that you almost always get a chance to look things over in person before you buy them.
Sometimes you're the windshield, sometimes you're the bug.....