Excessive nearside tyre wear and notchy steering

Hi all,

Ive been keeping an eye on my nearside tyres as they are showing excessive wear on the outer edges of both front and rear tyres. This also seems to go along with a heavier slightly notchy steering wheel too, but maybe coincidence?

Anyway, tyres are budget crap that was on when I bought the car 21, but they were almost new and no signs of wear. I've noticed the wear since December and monitored the tyres. Pressures are correct at 38 PSI all round, although I have leaky valve seals on all four corners caused my moisture corroding the valve seats. Have to pump up once a week but they never go below 34 psi.

The car pulls to the left a bit and so im thinking the 4 way alignment must be out if its effecting both front and rear near sides. I'm going to have to replace all four tyres at same time as all four are cheap and different, and I want the same grip and performance all round. I'm not made of money by any means and its £600 for four new CB rated tyres and another £150 for 4 way alignment.

I'm just after any thoughts on the wear and pulling. Wheels are good, no bangs or potholes or crash damage. I don't have £750 for tyres at the mo and they still have 3.6mm tread in the middle.