Multiply two irregular series (Influx/flux)

After reading a lot of forums I still can’t figure this out…

I have two irregular series. The first one reads data from my power cabinet ([kW], one sample every ~2nd second). The second one is the price ([local currency / kWh]), 2-3 samples every hour.

My intention is to calulate the total cost for a given time range (multiplying consumption and price, and probably integrate under that curve/graph?).

from(bucket: "amsdata")
  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)
  |> filter(fn: (r) => r["_measurement"] == "consumption")
  |> filter(fn: (r) => r["_field"] == "kW")
  |> aggregateWindow(every: v.windowPeriod, fn: mean, createEmpty: false)
  |> yield(name: "mean")

from(bucket: "amsdata")
  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)
  |> filter(fn: (r) => r["_measurement"] == "spotprice")
  |> filter(fn: (r) => r["_field"] == "price")
  |> aggregateWindow(every: v.windowPeriod, fn: mean, createEmpty: false)
  |> yield(name: "mean")

Power consumption and price

I will appreciate your help :)