This is what I use for case estimation:
Cases per pound, cleaned, spent primer intact
9mm: 116
.40: 100
.45: 80
.380: 145
.357 Sig: 96
.45 GAP: 86
.32: 168
.38 spl: 100
.357 Mag: 90
10mm: 96
FN 5.7: 124
.25 acp: 260
.30 Luger: 120
.38 S&W: 120
.38 Super: 104
9mm MAK: 124
.45 Colt: 60
.44 Mag: 60
.30-M1: 100
.223: 75
.308: 40
.30-06: 35
7.62x39: 54
.50 AE: 48
.30-30: 52
As far as pricing goes, check the Trading Post on this forum, look at closed ads, and see what stuff sold for.
Scrap value is $2 a pound, go up from there.
Bear in mind that unless you have something rare or expensive most people won't bother with less than flat-rate USPS box quantities to amortize the shipping across more cases.
Lately,
3 cents for 9mm
4 cents for 38 Special, .380 and .40
5 cents for .32 ACP, .357 Sig, .45 GAP, 9 MAK
6 cents for .45
7.5 cents for .223 or 30-M1 or 10mm
10 cents for Magnums or other large revolver or most common rifle calibers
Plus shipping (USPS Flat-rate is easiest)