Coming from someone who started with low budget tools, learned to make do, made some money at woodworking, then upgraded tools, I have one piece of advice:
When it comes to hand tools, you are only frustrating yourself by buying cheap tools. I don't own ANY 300$ hand planes, or a 100$ DT saw, but I also hated planing and hand cutting until I found a decent quality tool for the job. If you are that strapped for cash, buy used, or wait.
I used to cut fret slots for fingerboards with whatever thin kerf hand saw I could find, and I did it well. When I upgraded to a proper fret saw that was designed for the job, and really only cost marginally more than a cheap saw, then cutting slots stopped being a chore, and started being much more rewarding.
If your budget is less than 20, then wait a week or two, double your budget, and start testing out mid-entry level saws to see which one feels good in your hands.