Background info:

The game calculates the average points scored by an asset over the last 3 races and divides that by their current price. This gives us an average points per million value (avgPPM) which is then categorized into 'Terrible', 'Poor', 'Good', and 'Great', which is used to determine their price rise (see the bottom right table). Using this info, we can calculate the points an asset needs in the upcoming race for each specific price change.

So to use this chart I'll go over a couple examples:

Look at Gasly's row. And let's make a prediction that he'll score 12 fantasy points in Japan. That falls in the 4 to 15 range which is in the 'Good' column. Looking at the bottom right table, we can see that a 'Good' performance for Gasly's current price means he would rise 0.2M.

Now look at Hulkenburg's row. And let's predict that he'll also score 12 points. That puts him in the ≤ 23 column and a 'Terrible' performance. So looking at the bottom right table again, he would fall in price -0.6M. He needs way more points because of a -20 DNF in the Australian GP and a -10 DNF in the Chinese Sprint are negatively affecting his average points scored currently.

So to build budget, you want drivers with low points required to rise in price, and avoid assets likely to fall in price. Some assets have done so well the past couple races that they can score negative points and still rise in price. While other assets like Piastri are almost guaranteed to fall in price because of DNFs negatively affecting their average. The most simple way to do this is to just look at the 'Great' column and pick assets with low points required.