They are $15-$30 & will be one of the best investments you can make for your posture & muscle building journey.
I get asked all the time what equipment should I buy & since I usually just use my bodyweight
I don't have much to recommend but a pull up bar is essential to get stronger.
I recommend doing sets of 10 pull ups
But if you can only do 3-5 pull ups before not being able to pull yourself up anymore its OK.
Do 5 sets of 2-4 reps in the morning, in the middle of the day & again
at night.
Or for breakfast, lunch & dinner as I would call it.
This will develop your strength & increase your reps over time.
Soon you'll be crushing sets of 15-20 pull ups & when you are able to do that amount of reps crazy things
happen.
Not only will your back muscles get massive but your strength & explosiveness goes trough the roof.
And at this stage practicing for more advanced skills like muscle ups becomes a lot easier.
After a month of using it you will be asking yourself why didn't i have one before? ;)
Keep having a killer weekend,