Some advice please.... Limited $$ what should I spend on FIRST?

My Best Friend and I live together.  He has a KILLER Audiophile system centered around his Martin Logan 15A's.... I'm not looking to reduplicate that.

I will be using his Theil's speakers that are hotroded.  I intend on getting the ML center channel speaker and need a decent 2.1 Amp to drive the 3 speakers.   The choice I am struggling with is either spend about $2,300 on a 75" 4k TV and that will free up ~5,000 -6,000 on the amp.  OR  spend about $2300 on the amp and the rest goes towards a projector and screen.  Either way, the 2,300 will be a temp fix until I can save more $ to start filling out the HT system... I simply don't have enough $$ to get everything at once.... SIGH its always never-ending pursuit of upgrading lol