I Need An Estimate

I would estimate $300 using Atlas snap track with out the cork roadbed. The cork is probably $20 for a box of 12 triple sections that makes 90 plus feet of single track bed. Flex-track would be less. Go to www.atlasrr.com and click on the layout tab.
 
I'll add my $.02 in:
Go with flex track... cheaper, smoother, no derailments. I have had lot of bad experiences with EZ-Track. If you use "real" techniques on a 4x8 then it will be a real model railroad.

EDIT: Wording