I guess the first question is why? Are you looking at doing this as part of your repair business or is this more of a hobby/sideline work. That makes a big difference. If this is for your business, I would say you need to invest more. That said, some techs do amazing work with limited tools but the cost is hidden in the long hours of practicing and perfecting technique to compensate for the shortcomings of the tools.
The second question is what? What you plan to repair also makes a big difference; large multi-layer boards, high density smartphone logic boards, massive GPU's or small surface-mount passives? In general you need equipment that can deliver massives amount of heat very quickly. The lower cost stations often struggle with that.
In general, most people who do serious work generally outgrow their Aoyue-type tools pretty quickly. Without getting in to the expensive stuff (higher end Hakko, JBC, Weller etc), you could look at the Quick 861DW Hot Air Station or the Hakko FX-888 Soldering iron.
If you are just looking for hobby equipment, then the Aoyue stations will work fine to get you started. I would check out the forum at the EEVBLOG...lots of detailed discussions over there.
Come back and tell us more about what you want to do.