I paid about £250 each for my 2 x 2nd hand One10s about 3 years ago. If I had to pay todays new price of £449 or £489 I'd probably stretch to just 1.
As for guitars, I've seen the 2nd hand value of mine rise between 50% to 100% over the last 3 or 4 years. And these are not high end models, just middle of the range.
My amps, new, are now about 20 to 30% more over the last couple of years.
The price rise forecast for TEA of up to 50% is really serious though.