The only guys I'd be targeting over $550K at this point would be the Riddler, Dunks, Crae, Steele, Oliver and also probably the two big ruck dogs as your
"must haves".
Options like Titch, ZM, Tarantula etc are a little better suited to DT formats imho. This has been exacerbated this season with CD reaming them on a weekly basis as many of their owners would attest to based on the gameday rants I've read here the past few weeks.
Tracc does have some appeal if he can clean up his disposal currently 8th in turnovers and 3rd in clangers but I just think there are better options. So if you can't afford any of the must haves I mentioned above you are probably better served saving up the funds and bringing one of those fellas in the following week if possible.