1. If you want to build a PC, never ever go below Intel I5 or AMD Ryzen 5 level. Or you will be upgrading big very soon. Upgrading too often costs actually more.
2. If you do not have the needed money to reach nr. 1 yet, it is better to save up and postpone the build, if possible.
3. If you can wait, waiting is always the best. Wait always for the next generation, if you can.
Some thoughts about frequent upgrade instead of getting some performance level directly upfront:
e.g. instead of going directly to R5 1600, you go get R3 1200 and then R5 1600. You are paying actually those 2 procs. You are actually wasting money on that r3 1200.
Avoid this, if you can, but sometimes, such a thing is not avoidable....but really try to avoid
These 3 principal is more or less, what I have been doing since years.
My updates intervals can also be called slow compared to most of the people in this forum, I think.
Q4 2007 from D805 to Q6600+HD3850
in Q2 2011 from HD3850 to HD6850
in late Q4 2015 from Q6600+HD6850 to E3-1231v3+gtx970
in Q2 2015 from a single gtx970 to 2x 970s
in Q3 2016 from 2xgtx970s to a single gtx1080
I am still running that E3-1231V3+GTX1080 until today Q1 2018. Still holding back from hitting the upgrade button. Ryzen 7 1800x and I7 8700k are very tempting tho'.