Unlike other posters, I think that Smart will have a strong market in RFA. He's a good young player. I think the Celtics should try to extend him to any deal which doesn't plunge us into the LT.
The LT line for '18-19 is projected at $121m, and we currently have $107m committed for that year. Therefore, it's reasonable that we could sign Smart to 4 yrs/$48m and still have room for some minimum salaries without going into LT next year.
This type of move makes sense because what matters isn't Smart's exact salary, it's the LT line:
-The C's aren't going to have cap space the next few years anyway. If we end up paying $12m/yr instead of $9m it isn't a huge deal - it doesn't affect our ability to sign FA's.
-On the other hand, if we end up paying $15m per year in RFA, it's a big problem because it puts us into LT territory and sets us up to be paying the repeater tax in a few years. We don't want to be paying the RT just as GS starts to decline just because we cheaped out and tried to save a couple million dollars by letting Smart hit RFA.
Obviously if Smart and his agent think he's making 4 years/$80m next season, then all bets are off on an extension. But if their expectations are in the right ballpark then management should push for an extension that allows us to avoid the LT next season.