Buy it now or afterwards. It won't make much difference, as people like myself who've bought a Vulture now, will be getting a credit rebate once the discount goes live.
https://forums.frontier.co.uk/showthread.php?t=124528 In a minor update released before the end of the week we’ll reduce the price of non-trade ships and abolish the way fuel costs are scaled by ship type. What’s more, some of the smaller ships, like the Sidewinder will gain a powerful new advantage as their reduced profile makes them more effective for smuggling. These are minor changes but ones that dramatically increase the importance and viability of craft less suited to trading.
It's one of the developer replies later in that thread. I'll find it
Originally Posted by CMDR Reza Malin
Oh actually i have an important question Michael, if you could please.
If players own a ship that gets reduced in cost, will they receive the same sale price minus the usual 10%, that they bought it for?
For players who currently own those ships we will provide a credits rebate for the difference - however this will happen after the price change.
Michael