I'd say buy a new mid 2015 Macbook 15inches, some vendors might have it in stock. I recently got it for around $2000 USD in Pakistan. It's Core i7, 16GB RAM and 256GB SSD.
My new 15" MBP 2015 just arrived from Ebay in the US. $1740 total which is about $400 less than you'll pay at the Apple store.
I think the 2015 model has now replaced the older 2012 model (last that had upgradable parts) as the MBP that power users go for, even though it's almost $2k for hardware that'd be $800 on a typical windows machine.
This is what I did when upgrading last year - bought a used one on eBay (which is a first for me - normally buy them new) - 2015 15" fully maxed out (fastest i7, 16GB, 1TB) and including the GPU, so it basically benchmarks only slightly slower than the top of the line current model.
I already had a TB2 hub and other TB2 peripherals and extra MagSafe 2 power supplies, so no additional investment in adapters, etc.
The kicker was the unit I bought has been purchased less than a year before I got it, so it was still eligible for AppleCare (you can check this w/ the serial number that most reputable eBay vendors provide). The time has probably passed for this, although you could still get a unit where someone else has already gotten it.
Yes, having upgraded from one I fully regret this decision, mostly because of the keyboard and the £2000 after trade in. I’m actually a big fan of USB-C, it’s much better.
Not to bring this up in every usb-c comment, but what do you do for backwards compatibility? I consistently (nearly daily) find myself having to connect older USB devices into my laptop, but end up grabbing an adapter/dongle to connect the device. Flash drives, external hard drives, and SD card readers are my main issues.
I actually have a dongle thing with monitor pass through, older usb, sd card reader, mouse etc on my desk. Get all of these with one port.
Bought a cheap usb c enclosure off Amazon for backups too (swapping the hd) and I love it when I buy a new device that has usb c because I only need the cable that comes with my MacBook for camera and wireless headphones charging. So actually I’m nearly dongle free at this point. Still think it’s a real shame they didn’t keep the inbuilt SD card reader.
I guess it depends on what work you do, personally I only rarely (if ever) use USB devices, but for the single one I have (a document scanner) I just leave the dongle plugged into it so it's basically part of the device - if I ever grab the device it's got the proper dongle with it already.
There are a few left from reputable sellers on Ebay and sometimes online vendors for around $1750. Without tax, that's about the same price you'll pay refurbished at Apple.
I think the 2015 model has now replaced the older 2012 model (last that had upgradable parts) as the MBP that power users go for, even though it's almost $2k for hardware that'd be $800 on a typical windows machine.