I don't think you could have either of them for a similar price. Of course they would be much better signings for a "win-now" club in MLS, and that is disappointing for us. But all 3 are playing in the EPL right now, none in a club likely to be relegated, and both Walcott and Welbeck have annual salaries of more than 4 million US$ and Rodriguez more than 3 million US$. Those salaries were agreed on years ago in what was likely to be the last fat contract for any of them, but it is still debatable how much salary they would command in MLS. All are over 30, and in the case of Walcott and Welbeck injury prone. They may be available for free at the end of their deals (or not, Southampton apparently wants to keep Walcott, who is on loan from Everton), but their salaries would made them over-30 DPs.
The guys CFG is reported to have gotten from Uruguay and Brazil are 23 and 20 y.o. and cost reportedly 3.5 million and 1.2 million in transfer. Both will be on TAM level salaries or less (I'm guessing Rodriguez will have to be a DP because of the transfer cost, although I don't know how that works when it is a loan and not a transfer to NYCFC)
So it's really IMHO an apples-to-oranges comparison.