Pricing ideas

I'm looking for some pricing ideas for prints and, especially, for digital downloads. I sold one today - before I went Pro here on smugmug - and I literally gave it away based on personal use vs. commercial use. The picture will be used in a TV commercia as a background.

I went to some sites and saw some pricing but I was wondering from some experienced sellers what reasonable pricing is.

digital - personal use from another site
low res - $25
hi res - $100
Original - I haven't seen this pricing used. I believe it's because sellers would rather sell prints than a digital "negative" that someone esle could print tmeselves...is that accurate? Or set pricing for both presonal and commercial orginals the same to prevent this.

digital comercial use
low res - $230
hi res - $245
original - $345

Is this realistic inthe market? When I told the videographer my price of $25 for a low res he said that was reasonable. I guess! Ah, the difference a day makes.

Thanks for all your help as I start to actually sell!

Terry