Harsh but fair.
Ultimately coil overs can do what ever you want them to do; damping, rebound, spring rate etc.

Unfortunately the budget end of the market tend to be less well resolved both in terms of performance across a spectrum of uses (road, track etc), and also despite looking great when new tend to deteriorate fairly quickly and not wear so well as better crafted (and more expensive) items.

Buy right, buy once (or words to that effect) but it will be comfortably double your budget.
That said, the good stuff retains it's value for that reason and is also eminently serviceable, so if you need to sell them on there's always a market for them.

Right now that looking for a used set could be an option for you? But if so, to limit more expenditure try to aim for stuff which has had a service, or calibration recently so you know they're still performing as they should.

Cheers
Iain