>>5844623well lets see here, water color is the cheapest buy in at about 70$ for good student grade, professional grade is double that+10$ per sheet of paper, granted they are large sheets, but thats good paper
acrylic is a special kind of pain in the dick because of its dry time, but lets go this way, but you have 2 options, normal shit that drys in a few minutes or 'exotic' shit that dries over the course of an hour or so, 1 day for touch dry, for faster dry shit, you are looking at 80$ in paint at 60ml each and probably another 30~ in brushes for long dry, probably around 100~$ for long dry depending on color, then there's the mediums too to thin it out, make it matte, or hopefully stunt drying times just a bit longer.
then oil, this starts at around 200$ for paint for something good, not to mention the chemicals you need to use that can auto ignite from just air contact, the need to have a room dedicated to painting due to the chemical vapor, and then dealing with the chemicals because you cant just toss them like you can with the other two, paint realistically will end up costing in the 400-600$ range, because using low quality paint will frustrate the fuck out of you, and then you get the drying times, or realistically, the lack of ever drying, just a thin top layer will eve be dry, and even that can take upwards a week to dry between layers depending on color.
like I said, pain in the dick. realistically, watercolor is the easiest to just jump into but the unpredictable nature of how water color works means you would probably be better off with gouache, and thats a +50% to the price
personally I find painting fun, but for my money digital kicks the shit out of irl, however being able blend colors realistically in programs, is what I wanted because it makes it easier to mimic a real painting, rather then needing to go through the extra hoops of faking it digitally, this brings us a step closer to digital traditional.