I'm relatively new to the piano (on and off for 3/4 years). I really enjoy the Chopin etudes and thought I would try to study the Op 10 No 1. It has taken me ~4 days to get the first page down (at ~50-65% tempo; sometimes I can do 80-90% if I'm lucky). I'm not really sure how long I should be spending on one piece (as an indicator of whether or not it's too hard/easy), so if someone can clarify I'd greatly appreciate it.
Note: I'm not looking for anyone to tell me what to do or what not to do. I honestly just want an answer to my question and would appreciate it if posts like "you need a teacher" or "this is too hard for you" were left out.
If you want to play the entire piece at 50% tempo in 2-months, I'd say keep doing what you're doing. If you want to play the piece like Martha Argerich at the 1965 Chopin Competition, I'd say 4-days on page 1 is probably not a very good start... Keep in mind it will get exponentially harder as you continue: to go from 50 to 75% tempo, then 75% to 85%, to 90%, and that last 10 and 5% will probably take as much time or longer than it took to get from 0 to 90%. Assuming you haven't injured yourself by that point...
Excitement about piano is wonderful, but if you are genuinely asking "how long is too long", I hope you can take a step back and appreciate how infinitely open-ended the question is with the information you provided. And to dictate what answers are not acceptable reinforces to me that you obviously know the answer but don't want to hear it said out loud...
"relatively new to the piano (on and off for 3 to 4 years)" - I can't know anything about your ability from this...
"It has taken me ~4 days to get the first page down" - is that 96-hours? 2-hours per day? 20-minutes per day?
"at ~50-65% tempo" - how are you measuring tempo? What is your accuracy? Sight read? Memorized?
"sometimes I can do 80-90% if I'm lucky" - I don't know what this means.
Sorry to pick apart, but perhaps if you described more specifically 1) what you've done with the etude, 2) what other pieces you've successfully
worked on, and 3) what you intend to accomplish by spending time on a ridiculously difficult piece, advice and suggestions could be more targeted and helpful. The only responsible answers to your question based on what you provided are "it depends" and "as long as you want" ...
Good luck, and please know that people here are very eager to help others at all levels move forward. Think about it, it's in our best interest too - the better of a pianist you become, the more good music there is out there for everyone.