Whether you DYI or hire out, below is what I recommend:
Optimize for assembly. It is worth paying more upfront if it takes less time on site to put together. Plus there are less moving parts that can break, need constant tightening, lost/missing parts etc. A nightstand or dining with 70 pieces is a major bottleneck and keeps your team from moving onto other tasks, whereas one that is already assembled might cost $50-100 more but only takes minutes to unpack.
Buy nice or buy twice. If you follow my advice above you will likely buy quality by default. Cheap items will break sooner and require replacement, and will make your place look cheap overall.
That said, you don't want to overspend either. If you buy something too nice that is also light and compact then a guest may help themselves to it. Shoot for middle of the road kitchen utensils, blankets etc
Otherwise it is pretty easy to have most of your stuff scheduled to arrive at the same time. Couches, dining and bedroom sets are the only things that should require a delivery.
Get a roll away dumpster too- the amount of packaging waste the setup generates is staggering!