How do I increase the start price?

I usually go in to the price via the Items I'm selling folder then click on the Edit Price & Quanitity button.

https://www.trademe.co.nz/MyTradeMe/Sell/Current.aspx

which then brings up this screen to change the price.

Much quicker and easier than going in via the edit screen if the price is all you want to change. Never fails to update correctly.

Those examples are for fixed price Buy Now listings, but same works for std auctions.