Thinking of Changing Rules on Commissions

More specifically, my story commissions. I'm finding that I'm underestimating myself on how much a particular plot will take, page wise. While it's not a loss, considering that I have a job and the extra 8-12 bucks is barely a problem, I feel I should handle myself more professionally. The trouble with storytelling is that there's no average. It's all based on my imagination and how I feel best to progress between points.

So here's what I'm thinking. I'm of the belief that, just like a store, you get your merchandise (story) after you pay. Waiting until the story is finished to collect payment runs risks of people stealing nearly complete WIPs. Not that I've had that issue yet, thankfully, but as I hopefully post more and get more exposure, it could happen.

Instead, I'd collect what basically amounts to a security deposit, which would cover approximately eight pages of work, since that's what my usual stories run by. Then once the story is complete, I'd collect the rest of the payment.

I'm also considering possibly raising the price to $3 a page rather than $2.

But this is just my opinion, I'd love to hear your guys' take on it.