so i've been looking at the art trading forum and noticed that even though the rules say that selling art commissions for real-world currency is allowed, none of the threads i peeked into were doing it. is there just not a market for it? or is there some other thing that makes people not want to sell for usd? or is it super common and i just happened to miss every thread that did it?

also, is there an agreed-upon exchange rate from usd to gold? like, if i were to price something like this

at $15, what should i expect people to be willing to pay in onsite currency?