I thought this thread had died a death.. ahh well. If you've got ID and Excel (or any other spreadsheet program that'll let you make a series of numbers) you're sorted. I'll describe the process using Freeform VDP which is easiest on the ripping times, but if you want to rip every item on every page I ain't gonna stop you.
1) Make a spreadsheet with two columns titled 1-250 and 251-500. Fill these columns using (if you're in Excel) a series fill and then use a custom number style if you need them to read 0001. Save this as a CSV called Cut&Stack 1-500 2up.
2) Impose your job 2up in ID with everything except the numbering. Spool this to the RIP.
3) Duplicate your ID imposition and rename it "numbering set-up" or something. Drop text boxes over where you want your numbers, one for each side. Using the data merge import your CSV and put 1-250 in one position and 251-500 in the other.
4) Delete everything off the page except the number boxes and get ID to do the merge. Save this file as a "numbered" or summit. Spool this to the RIP.
5) Go to yer RIP. Mess around with the job settings on the artwork part of your job until you're happy with what the printer is spewing out. Print this to a Freeform master and save the preset.
6) Go to yer numbering file. Tell this to use the freeform master and the preset from earlier on and print away.
T'easy. By the way I usually spool one page of numbers for a quick test before running the full job. Gives the finishers a cutting sheet to rule up as well.
OR
Spend a stack of money on yet another piece of software to learn that can do it for you.
It may seem like a pain (because it is) but once you've done it a few times you'll find it goes pretty quick and if you save your cut&stack CSVs you can often just take one off the shelf instead of making a new one. Did I mention it reduces the ripping time considerably? Although feel free to go ahead and spool 250 pages of the same artwork if you want, I used to until I was intrigued by the VDP tab. If you haven't got a Fiery there's probably something similar on the RIP yer using, if not, bad luck.
