I actually expect him to be somewhat cheap compared to other free agent pitchers, because of the health issue. And by "somewehat cheap", I'm referring to the total money and the number of years, since to me as a fan, years are more important that the cash.
Last off-season, DL mainstays Michael Pineda and Drew Smyly both signed 2 year $10mill deals even though both were expected to miss all of 2018. Eovaldi is probably looking at a lot more than $5mill per, but probably not looking at more than 2 or 3 years, because no one wants to go long term on him given his health history...