Read above
That quoted post was totally useless, here's a guy who is asking what be could do with his 300 bucks and you come on here to an Amiga fan based webste and basically say everything Amiga related is s**t. Opinion respected (just) but wrong.
I would get a Mediator, that way you can get noticeable PCI performance upgrades at affordable prices. On top of that you still have a 'Real' Amiga, not a SAM or anything of that sort.

$300 Won't get you far towards a SAM even if you sell off all your gear.