This research report (130622 SAN technology and implementation options (1.0).odt):

This report can help choose between NAS and SAN. If SAN is chosen, this report can help choose an implementation option.

The options in this report are all designed to minimise cost. Each includes an initial 9 TB of raw storage. They range from INR 2.5 lakh (including international shipping and import tax; EUR ~3,000, USD ~4,200) for a fully redundant system to INR 30,000 (EUR ~380, USD ~500) for a truly minimal solution based on expanding an existing server.

The conclusion is that price of entry into SAN can be progressively reduced as features of a tier one solution are dropped:

Each price reduction comes with a performance reduction but one that may be acceptable in context.

An associated spreadsheet (130622 SAN implementation options costings (1.0).ods) has price breakdown for each implementation option.