Modeling yeast biochemical pathway using enzyme kinetics
You should take a look at SGD (the Saccharomyces Genome Database), and in particular YeastCyc. Some protein information pages at SGD give estimates of molecules per cell taken from this Nature paper.

Added later in response to some comments:

The question asks about levels of metabolites and of enzymes, not of transcripts. Microarray data can be, at best, only a guide to levels of proteins. Estimating the levels of metabolites from microarray data is a complete non-starter since there are entire layers of regulation that will be ignored. Just to give one example of a pitfall in this approach: you could have high levels of transcript from which you could you could infer high levels of enzyme, but that enzyme could be inactivated by a post-translational modification.