How much is to much to spend on a car?

[arthur t]

So I bought a 05 wagon this summer, it's great fun and as I got the SL the inside looks gd to.....But the rear shocks have gone and reading the info on them seems like it would be worth getting a better rear anti roll bar at the same time

So my list on my new second hand car is already requiring:

2 x rear shocks
4 x new springs (improve corners & looks better)
1 x anti roll bar
All new mounts
Maybe anti uplift kit...

Maybe remap and filter (just bought sti back box)

Etc etc.

My point is what is sensible to spend on a car now the new Wrx sti cars are coming down in value so much.