I forgot to add in laptop and mic for measurements. Most already have a laptop and you can get a good mic for $75. You might need more for Room than I spent. My room was already pretty dampened and restricted on what all I can do since it isn't dedicated. IMO speakers and room are your most important considerations. Invest the most in speakers you like it's easier to upgrade the other items unless you have enough money to get everything you want at once.
For my system.
1. Speakers $10,000
2. amplification including DAC $4000
3 .Source digital <$1000
4. cables<$200
5. Room $300
