You mean one of the most basic rules in the MB that allow prices to vary?

Be careful what you ask for when it comes to economics. Funny thing in economics that is unique to all other system is it fixes itself - it means if something were to adjust in the economy, you can expect every single required adjustment is made in prices, supply, and demand to accommodate that change. To succeed in the MB, you have to be the reason for price changes. If you arent, all you are doing is indirectly paying people like me who are manipulating the MB.

Want your items at a reasonable price? Buy in bulk, identify trends with low demand/high supply (HINT: Usually always after a high demand/low supply period because sellers always overcompensate), and understand the items you buy: how they are obtained, all applications they are used for.

Bottom line? Be smart with your gil and do the research on your buys - or you will be paying someone like me inadvertently to do it for you.