5 years has made a large difference in prices, as shown in this graph quoted in TFA: https://www.paulzimnisky.com/Price-Evolution-of-Lab-grown-Di...

Assuming you mean "late 2018" by "about 5 years ago" (because that's where the graph has a 1.5:1 ratio), that $1200/$800 diamond was probably about 0.2 carat (obviously depends on the other Cs), and would likely be around $1200/$300 today.