I keep vacillating between trading for established talent or just drafting players and building organically through the draft. Typically, I'd say a mix is the best way to go.
In regards to the Celtics situation, things are a bit different... we have a management and fan base clamoring for a star, and willing to overpay to do so (e.g. last year's trade for pick #9 with Charlotte that fell through). This is a very bad combination - patience is virtue sometimes, and I do not believe in overpaying as a general philosophy. Further, it looks like Cousins, Butler, Love and Griffin are off the market; and even if they weren't off the market, it would take a gross overpay to acquire any of these players.
As a result, I am starting to believe that the "un-sexy" choice here should be to build through the draft and see what happens. If we get a top 2 pick, I think we should keep the pick (especially for Ingram, but I'd be open to trading Simmons since I don't trust him for some reason). Even if we don't get a top 2 pick, I am fine with taking Bender...BUT even though he is only 18 and super skinny, I still would want him to play on our team next year just like the Knicks did with Porzingis. He wouldn't need to play 25 minutes a night, but give him some playing time and a chance to earn some minutes. Conversely, if we don't think he's ready and don't bring him stateside, then I guess just leave him in Israel for another year or two. The same thinking goes with Jamal Murray or whoever else we may be able to pick.
In the above scenario, I think we should let Sully, Amir and ET walk (unless ET gives us a super sweetheart deal), and play this years rookies and last years draft picks. I think we still make the playoffs and even being better than last year isn't so farfetched. At the same time, due to having 8 picks this year, it'd be nice to consolidate those for future picks or better picks this year (as we can't play 8 rookies) or even trading some to get Faried from Denver to replace Sully.
This may not be the "cool" or "fun" option, but it may be the best, unless we can somehow get a 'star player' in a deal that is not a COMPLETE overpay.