I agree with the others, you should def go for real money! Nidoqueen looks great, love the pose and colors! If you're looking for price estimates, deviantart or toyhouse can provide better examples on how people charge. I'm not very good with rlc prices bc every artist has a different idea on that but like I said, looking at people's shops on here or other sites can give you a better range. From this forum, I've seen people charge from $5 to more than $30, but again, it's all under different circumstances due to styles and experience.
I've also seen plenty of recent shops go with 'pay what you want' where people post offers of their character & amount they'd spend but that's usually with TBT. Maybe that might work for you?
It also honestly depends on what you would be willing to draw and things you're not comfortable drawing. People want to know if you'd be willing to draw mayors, OCs, animals/feral, etc. so when opening up commissions, it's important to reveal all that and have a few examples. One art piece can be a little tough to give a rate.
Real life cash commissions on here can work but just keep in mind many forum users do not have Paypal. I honestly do think you'll get people interested either way!