Their scanner is rated at 4000dpi, and you can choose the file sizes. Large is 25M IIRC.
Go here:
Photo Lab | Precision Camera & Video and click on 'Scanning', then click on film.
This was lifted from Precision's website: Looks like 4-5000 DPI to me
Low Standard High
Type 72dpi - jpeg 300dpi - tiff 500dpi - tiff
35mm N/A $8.99 N/A
*Scanned to size: 8”x12” 2400x3600px
120/220 $5.99 $8.99 $14.99
*Scanned to size: 8”x8” 576x576px 2400x2400px 4000x4000px
4x5 $5.99 $11.99 $22.99
*Scanned to size: 8”x10” 576x720px 2400x3000px 4000x5000px
ESTIMATED TURNAROUND: Next day at 5:30pm Monday through Friday.
* File format desired (PSD, TIFF, Jpeg) Default settings are: .tif RGB file on a PC format CD-ROM
*8”x12”, 8”x8” & 8”x10” are common sizes of scans. Your scan may be larger or smaller and therefore this chart should be used as a reference when figuring your final ppi.
IIRC, I pay about $13 for processed roll with a CD of large images that I can't do at home, but it's been a while, so I may be off some.