According to the AP Stylebook, “more than” and “over” can now be used interchangeably to indicate greater numerical value, and “less than” and “under” can be used interchangeably to indicate lesser numerical value. Prior to the rule change, the only acceptable use of “over” was as a locative, a preposition designating the physical placement of one thing relative to another. (Source.)
Choosing between more than and over with respect to numerical values seems to be a matter of style now, not grammar.
If we check the Cambridge Dictionary, we get
over preposition (MORE THAN)
Most of these rugs cost over $1000.
Children over 12 (= older than 12) pay full price.
So for example, Most of these rugs cost over $1000 is equivalent in meaning to Most of these rugs cost more than $1000.
You will often see and hear people using over in this way, at least in the US. Either option is acceptable.