As a buyer, I prefer individual prices instead of grab bags. Owning as many pins as I do, I want to avoid duplication when I can. I'm always afraid with grab bags, that I'll spend a bunch of money and end up with nothing I want. If CM trading were better, or I was doing more online trading of OE pins, or could attend pin nights, maybe it would be different.
You could start out with individual groupings of prices. $3, $5, $10 pins, etc. Easiest thing seems to be to arrange in your pin book by price and then take a picture. You could always make grab bags out of what doesn't sell after however long you want to run a sale. But it gives you a chance to sell to people who don't want grab bags, as well as getting the grab bag type of people later.
However, my advice is kind of moot anyway, because I have no money to buy pins from DPF sales because BatB PODM, Pluto's Christmas Tree PODM, and New Fantasyland completely wiped out my budget until mid-Jan at least. Which is really driving me nuts, because at least 5 people are running sales that I desperately want to purchase, but I just can't. So note to people running sales: I want your pins, I just can't afford it now.