14 CFR 61.65 requires minimum 40 hours of flight time for a Instrument Rating.

This required time includes:

A total of 40 hours of actual or simulated instrument time, including:

At least 15 hours of instrument flight training from an authorized instructor in the aircraft category for which the instrument rating is sought

At least 3 hours of instrument training that is appropriate to the instrument rating sought from an authorized instructor in preparation for the practical test within the 60 days preceding the date of the test

At least 50 hours of cross-country flight time as pilot in command, of which at least 10 hours must be in airplanes for an instrument—airplane rating;

For an instrument—airplane rating, instrument training on cross- country flight procedures specific to airplanes that includes at least one cross-country flight in an airplane that is performed under IFR, and consists of:

       A distance of at least 250 nautical miles along airways or ATC-directed routing

       An instrument approach at each airport

       Three different kinds of approaches with the use of navigation systems

For the complete requirements see 14 CFR, § 61.65 Instrument rating requirements.

Note:

These hours are the minimum amount of training in each area as required for an Instrument Pilot Rating by the FAA.

based on minimum training times of 40 hours in a Piper Archer II, the total estimated cost of training is as follows: