Ideally, you want the temperature to do something like this:
The Hakko FX-951 sells for $225 on Amazon with excellent customer reviews. You can get it at Banggood for $90. Banggood has never disappointed me.
In case anyone thinks the Banggood item is is a bargain, just be aware the advertised unit is not a genuine Hakko, but is styled after the Hakko FX-951 i.e. it is a copy.
I second this. The popular brands sold by these Chinese sellers at drastically reduced prices are not genuine. I came across some articles showing a comparison of the dismantled products, genuine and non-genuine Chinese copies.