I am just going to chime in with our own personal experience buying a new construction home in the SE Florida area. The below relates to the exact same home model (a 2800 sq/f 4/2.5 that is certainly a very nice house, but nothing out of the ordinary).
In all cases, the prices do *not* include the lot premium nor any options (and, trust me, you do need most of the options if you want things like decent paint and doors). The lots are usually $30K and up. Many are $60K and one just sold for $199K! (again, this was *only* for the lot!)
2019: development of the community begins, and homes start on average around $440K.
February 2020: price of the model we like is $460K. We request an estimate for what would be our own build. Our final, out-the-door price with a lot and options was about $525K. We almost bought then, but Covid was beginning to worry everybody and we decided to wait. Big mistake.
December 2020: The same exact home model now starts at $509 (plus lot, plus options).
January 2021: It now costs $536k. We decide to buy. Our final price with the *by far* cheapest lot we could find (which was "only" $18K) and options (and after a temporary promo where they give you cash back on the options) ends up being $612K. I was mortified. To me, this number was simply obscene and completely unjustifiable for a nice but not spectacular 2800 sq/f home, but for circumstances that are too long and complex to explain here, we had to move, so our options were limited. We put our deposit down.
February 2021 (1st week): It now starts at $556K.
February 2021 (2nd week): It now starts at $563K.
February 2021 (3rd week): It now starts at $576K.
March 2021 (first half): It now starts at $580K.
March 2021 (second half): It now starts at $590K.
April 2021 (first half): $593K.
April 2021 (second half): $603K.
May 2021 (first week): $613K.
Today (May 8th, 2021): $621K.
So, we bought in January for an out-the-door price of $612K (includes lot and options). The same exact home, only about 3 and half months later, would have cost us close to $750K instead ($621K + $60K lot + options). That is over $100K in less than 4 months.
10 miles from this development, the same builder is selling *smaller* houses starting at $750K and with lots in the $150K range, which means that a 3/2.5 can end up costing you $900K.
A bubble? Or not? Come to your own conclusions. I know what I think.
EDIT: Just 1 county up north, the same builder is now selling *only* through a "this-is-just-the-base-price-now-make-your-offer" system, which was unheard of for new construction and encourages the "fighting" over starting prices we are all reading about everywhere, forcing an already-inflated price to literally balloon out of the realm of any common sense.