I'm an app developer, as I needed the laptop asap to work from home during the pandemic I couldn't wait the extra shipping time to build a custom configuration, so I went for the higher tier with the i9.
If you're on low budget, those are the priorities I'd have:
1. RAM (16 are enough but 32 better if you run virtual machines)
2. storage (512 is good enough actually, but 1TB will be ok for years)
3. CPU
4. GPU
I don't play games, so GPU isn't really important to me. You may have different priorities of course.
I can tell you the faster CPU is good for development, but I only save a few seconds for each build compared to my older MBP. Not a deal breaker.
If I had time to wait for a custom configuration I'd have built this machine:
2.6GHz 6‑core 9th‑generation
32GB RAM
1TB SSD
2999 is the price of the machine, while 2799 is the price of the model I got (I found a really good deal on it, that's the advantage of buying one of the base models)
The extra RAM is pricey, but it is easy to use a lot of it nowadays. I have a few simulators opened, plus web inspector and a lot of tabs in safari/chrome.
Sometimes I can see some swap has been used by the system. SSD are really fast, so if you swap a little bit you are not stuck with a painfully slow machine like it happened in the past, but the extra RAM would help sometimes.
I think my next Mac will have 32GB, as I said I was in a hurry and I found a similar deal on a 15" machine with 32GB of RAM, I didn't buy it because of the keyboard actually, otherwise I'd have gone for the older machine only to have more RAM