If you're not in a hurry, you could hang on until Apple gets its own silicon but there's no way of knowing how that will affect the price.
Looking around at the options for a new iMac, in the near future, to replace a 2011 one, I have had a brief look at what's likely to be happening with Apple's possible new release/design (in November ?); but also re: the price, wondering if there could be a Brexit impact on this, from 1st January, either due to a fall in the £ or something else - would that be plausible, or an irrelevance?
I would be glad of views from anyone on the most useful non-specialist source of advice on what to expect when, from Apple.