I would add 2 things to what has been said.

An index on the section field should make lookups of section efficient.

When I have done similar things, I have had prices in a seperate table with an effective date so that prices could be changed by a date and historic price info could be gathered.

So for your sale example, say that from August 1-8 you were having a sale then you would have 2 entries in the price table for your item one with the sale price and August 1 and one with the normal price for August 8th. A sale boolean could also be put in this table to indicate sale prices if desired etc.