A couple of quick answers... Some boys will go short time for 1000 or 1500 Or if a real primadonna 2000.. I'm over 65 I never paid more than 1500. I usually offer 3000 for overnight but I guess I am overpaying, but I hate to be cheap.
As far as a 90 day Visa if you are in America go to Thai embassy USA and you will find information on all that stuff. There is an official website in America for Americans traveling to Thailand ,you just have to Google it.