new MacBook Pro or wait for potential 2019 updates

I don't need a new machine. What I have now works great. And to be honest, it's going to get harder when I upgrade as I'll lose out on ports and have to buy new adaptors, and probably have to get a new Belkin Thunderbolt Express Dock (or something similar) and will have to be more strict with what is on my internal SSD as I currently have 512gb with a 200gb SD card installed all the time, but there's no SD card slot on the newer MacBooks and I am not sure I can afford 1tb on the next machine...

I'm not sure the MacBooks will get cheaper if I wait though. They just seem to be getting more expensive. And the value of my current machine is dropping all the time, and will drop further once the AppleCare runs out.

They hold their value better the more AppleCare they have left. And I have to think of the cash, especially currently as the new models are so expensive, plus they also require me to buy a whole new set of adaptors, a new hub, and double my internal SSD because they've dropped the SD card port. It's a huge outlay of cash so the more I can get selling my current machine second hand the better, all so I can cover the excess costs of an upgrade.

I have sold my last three machines on for two thirds of their original cost, so Apple machines are typically a great investment.

Right. Thanks for that.

But that's not quite the same as having a micro SD card inside your SD card slot all the time because it can sit flush with the machine and act as a constant additional 200gb of hard drive space. That currently allows me to have a 512gb SSD and have extra room on the SD card. But with a new machine, I'd have to get the 1tb SSD to give me a similar size hard drive without having to connect extra stuff on the go.

https://www.amazon.co.uk/BASEQI-aluminum-microSD-Adapter-MacBook/dp/B012F38H9A/