total novice looking for some advice

hello people, i'm completely new to 3d printing so new infact that i haven't even purchased my first printer yet, which is actually what im looking for advice on, been looking at the very cheap ebay prusa clones (around £80) researching these it seems the first thing to do is upgrade the lead screws, so was thinking of doing this at the time of building it however whilst im pretty computer literate (building, messing about with cmos ect) im not familure with editing 3d printer firmware, ie where to get the firmware, what edits i need to make or how to make them, so on this basis would it be worth buying one of these really cheap printers and learning as i build/print or would i be better committing a little more cash and maybe going for something like an artilary sidewinder x1
any advice will be much appreciated