Peat and perlite alone are not bad, mix this with an equal amount of compost and I think it would be good. In regards to vermiculite, I was at Walmart the other day and noticed decent sized bags of perlite/vermiculite for under $3.00. For a normal 4x4 bed, I think two or three bags would be enough.

Mike

Vermiculite is not a necessity. It serves similar functions as peat-it's just a little better at some of them. For my SFG I halved the amount of vermiculite and substituted more peat. Almost all my vegetables in my community garden have outgrown their counterparts in all of the neighboring plots.
Manure is cheap-$1.00/bag, but you can overfertilize with manure and compost. I think the 1/3 compost is an upper limit you might not want to cross.

Thanks for the tips!