/\$([\d,]+)\.(\d+)/

The one you have above is

/\$([\d,]+.\d+)+/i;

the difference is that you are matching a dot between
numbers, but in regular expressions a dot basically means
any char meaning you could match anything instead of the dot
for example.

“$324!234″
“$324×234″
“$324%234″

and plus the first one independently captures both the first and second number after a dot, making sure that it is a dot. you might wanna make a stronger regex though because in both cases you could match something like

first case
“$,,,,,,,”
“$,,0,0,,”

second case
“$,,,,,,,”
“$3,4%2,4″

I would recomend to remove all commas before getting the price
or make a more specific regex for the problem presented above

cheers!