To be an actor in a Thai movie/Thai drama or doing modelling here, is it even possible to get a work permit for this? How much does it usually cost a company to pay for a work permit and how long does it usually take for them to get it? I can't imagine that it would be really beneficial for them to even try if that person is only going to do very short work for them.

Oh, let's add musicians & DJ's to the list too.

The fees for a work permit are 750 baht for a 3 month one, 6 months 1500 baht and one year 3000 baht. In order to have the work permit issued would require a non-b visa.

You should have non-B Visa and WP even for a days work but... I have talked to a model once going to Vientiane for our visas with the same agency. As he said, how can a model get a non-B visa and WP because most of the time he has just 1 or 2 days work for each project, that means that he must have a new visa and WP for each project, return the WP and go to Laos for a tourist visa between each time he's working even if it's just for a day or two so it's just not a workable solution. Madonna on the other hand probably had a non-B visa and a WP just to sing for one night.
If you have work for a week or more I would highly recommend that you get everything in order.

I wonder, did Justin Bieber, Pitbull, Ne-Yo, Iyaz, etc. & whoever came to preform in Thailand get a non-B Visa and WP arranged for them?

The fees for a work permit are 750 baht for a 3 month one, 6 months 1500 baht and one year 3000 baht. In order to have the work permit issued would require a non-b visa.

This is INCORRECT YOU can get a WP on a Non O visa so a WP not does not need a B visa

All actors and singer get a special permit to work in thailand, there is a special immigration office for this purpose.

The fees for a work permit are 750 baht for a 3 month one, 6 months 1500 baht and one year 3000 baht. In order to have the work permit issued would require a non-b visa.

This is INCORRECT YOU can get a WP on a Non O visa so a WP not does not need a B visa

My spot was for the OP and was correct for what was posted there.

The fees for a work permit are 750 baht for a 3 month one, 6 months 1500 baht and one year 3000 baht. In order to have the work permit issued would require a non-b visa.

This is INCORRECT YOU can get a WP on a Non O visa so a WP not does not need a B visa

My spot was for the OP and was correct for what was posted there.

IN my opinion The OP is asking 2 questions

1 is it even possible to get a work permit for this? the correct answer to this is YES there is the following Visa's B and non o 2 types of visa not just one as YOU stated

2 cost your answer correct

you as being a mod Should give correct and precise answers, your answer stating only a b visa, gives the impression that if you are an actor or model with a non o you can not get a work permit which is incorrect very poor advice by you.

I knew an International model.She would model in many countries.She would only be in Thailand for A week or 2 at A time.I believe

The agency she worked for took care of everything.don't have any idea how it would work for A lone wolf.I would ask your agency