A problem with spending (T-minus 15 Days)

I start searching for deals on buying the games today. Wait, you don't have all the games? Why of course not. I played them when they first came out and basically wasted a fortune on them when I was a kid, but they were traded away or lost in some condition. Plus I want to play the updated ones on Gameboy Advance and DS. What I have with me now are:
Final Fantasy 1,2, 4 (Wonderswan Color, Japanese)
Final Fantasy 6 (SNES, as FFIII)
Final Fantasy 7,8,9 (PSX)
Final Fantasy X (PS2)
Final Fantasy XI (PC)

Now here comes the painful part. I'll have to buy a Gameboy DS. Besides that I'll have to repurchase all the Final Fantasy games coming before FF7 as well as Final Fantasy XII. It looks like it will be a big dent in the wallet, but I'm sure I can resell them easily. As for retail prices go, Amazon.com seems to be the lowest (along with free shipping).
Here are their prices:
FFI & II ($20)
FFIII DS ($25 used)
FFIV ($20)
FFV ($27)
FFVI ($30)
FFXII ($30)
That's about $152 total. It seems like a expensive endeavor, but before we jump to conclusions I will venture into the world of Craigslist and Ebay for cheaper alternatives, especially if I'm willing to stomach used versions.