The final public price target was stated as £495k very early, then updated to £595k a couple of years ago, where it has remained since.
I believe "the price is going up" is confusion about the discounted purchase incentive for early customers.
Early customers who were happy with holding higher development risk, are contracted to quite large discounts, in return for a small deposit that helps fund the development. These discounts have slowly reduced linearly to almost full price nearing 1000 orders. So all this talk of "the price is going up" actually just means that that as the risk curve asymptotes to zero, the discounts drop off and the price approaches the final retail price. Any person at any time has always been able to place an order for their acceptable risk appetite. If you're not happy, just wait until the milestone that you want to see, whether that is engine, prototype flying or the first 100 out of the factory and flying.