I agree with others that Sharpshooter isnt really a good feat to take on low levels.
The main advantage of sharpshooter is really that you can still hit opponents who have the higher ground as if they wouldnt have this advantage.
An ability that lowers your chance to hit by 5 points, which on a d20 attack roll (i.e. random values between 1 and 20) means 25%, isnt going to work too well, unless you are really very likely to hit in the first place already.
For example:
Your original chance to hit is 30%, activate Sharpshooter -> your chance is now 5%, so 1/6 of the previous value.
Your chance to hit is 95%, activate Sharpshooter -> your chance is 70%, thats 2/3 of the previous value. Unless your weapon does more than 20 points of damage per attack, you would be get higher damage ... on average. And your opponent needs to still have plenty of hitpoints for this to be effective, too.
So really unless you already have a very good chance to hit AND your opponent has still plenty of hitpoints, its probably not worth it.