I think all frames have tapered Head tubes now as a no cost option, certainly the longer travel frames do. My AM came with tapered and was delivered only two months ago.
The pricing in the uk was set a while back when the exchange rate was more like 1.11EUR to the pound. Momentum had to increase their prices because they were loosing money. The exchange rate has been a bit erratic the last two years so were now in a period when the frames look expensive in GBP relative to their EUR rate.
Ultimately if you don’t like the price don’t buy one. Alternatively you can always head to Germany and buy one from there.
Trust me though, you will not be disappointed with the frame.