How do you use the computer?
How much space are you currently using?
How important is portability?
Do you like the new keyboard and touchbar?
If 512 GB is a size you can work with, that opens up the prospect of the retina MacBook. If 8GB/512 is acceptable, that opens up the prospect of the rMB and MBA at reasonably affordable prices.
A 15-inch with a 1TB SSD will cost about twice that of a retina MacBook or MacBook Air with 8GB RAM and a 512 SSD. With the lower cost, you could potentially upgrade sooner when something better comes out. Further, you could purchase AppleCare+ and sell the system at the 2.5 year mark to recover a huge portion of the initial investment. With the retina MacBook and MacBook Pro, I would go as far to say that AppleCare+ is pretty much a necessity these days - and with this method, you would never find yourself in a situation where you were not covered.