If every starter got $15M and assuming that nobody else in that starting lineup made more than that, then that's more than 75% of any team's cap space. Last year's contracts were inflated due to a few variables. The door is going to swing back over the next three years (simply my opinion) where people will then be underpaid (relative to where the cap numbers settle). The crunch this year (again only in my estimation -- not based on anything hard) is that the low and moderate level guys will get squeezed relative to last year (i.e. no more Mosgovs, Delavadovas or Noahs). Ingles played great D and shot well but I really doubt anyone's looking at him to offer $15M. For the teams that actually have that cap space, it seems like there are more people available to pay $15M to than there are teams able to do so (I'd have to actually look, though), but I don't see Ingles as one of them when there are many other 'bigger fish,' so to speak.
tl/dr, someone is going to offer Ingles 45/3, I guarantee it.