What should i buy as my christmas present?

[recidivist]

First question is are you wanting to use only Amiga?What do you want from computer?

 $300 will buy new PC with Win 7 as smerf says;his options make sense economically even if his posts comes across as anti-Amiga.And the PC will let you run a very nice Amiga Forever emulation.
 
 If you want lots of free programs that will let you do nearly everything then Linux on PC is very good;Linux is still available for older Mac PPC so a Mac G4  would allow you to run  Linux,Mac OS and soon? MorphOS .

 If you want modern Amiga hardware then SAM IS the official Amiga solution despite the rather high price.

 If you want classic Amiga WITH improvements then Mediator etc is your path.

[recidivist]

I forgot to note than one can also run Virtual PC on a Mac G4 and thus run other OS  from DOS to Windows XP pro.So one machine could be MacOS/Windows/Linux/MorphOS.

[recidivist]

@platon42

"If you'd really want to stick with your Amiga, a Deneb USB card probably offers the most flexibility to add cheap hardware that you can use with any computer later."

A very good bit of advice.

Thank you .

We all should keep in mind that just about  anything except CPU upgrades can use USB with the proper driver.
 I've been thinking of usb for my classics but then the money went for a Mac mini G4-and now we hear   MorphOS will soon be  out for the Powermac G4 I already had.