If you know you spend $1500 on cafe coffee why not up your spend to $1500 for a better equipment? $600 split 50/50 means $300 each will not get a lot for your money unless you are looking at used equipment and even then not unless you find some cracking good deals or go the used Lelit combi way which is a grinder and espresso machine in one. $600 on a single item possibly will get you something a little more reasonable.
I am guessing $1500 at $4 a coffee = 375 coffees a year? If you intend to roast your own coffee beans @ approx $15/kg and 18g per coffee = $0.26 an espresso add milk for say $2 a litre using approx 200ml a latte = ($0.40 + 0.26) x 375 = $247.50 a year you will spend on coffee (no allowance for electricity and maintenance). So even if you round it up to $300 a year you are saving $1200 a year on your cafe coffees. So personally I think that justifies spending at least $1200 on your equipment...don't you?