Y-O-U A-R-E J-O-K-I-N-G!!!!! Are you serious.? They CHARGE you to renounce? FFS!!! Of course they raised the price given how many people will do just that if GOD FORBID Trump gets in.
The UK charges to renounce citizenship too, but it's 'only' £272 compared with $2,350 for renouncing US citizenship.
Also, if you want to renounce your US citizenship, you have to hold another citizenship first (as you can't be stateless), so unless you already have dual-citizenship with another country, you'd need to get UK citizenship too... which costs £1,236 (compared with about £130 back in the early 90s).
So, in total, to get UK citizenship and then renounce US citizenship, it would cost you over £3,000!