I'm probably overthinking this, but I'm wanting to make sure my first, large batch of mail hits during an optimum time, not one where people are going to be too focused on the holidays to act.

I have also mailed thousands of batches of postcards and yellow letters but was never consistent with it.

I would buy it in two batches. first batch is using the last sale filter to 01/01/2015second batch don't use the filter. 

If you know why you've set that price and why it's a fair offer you'll be more confident in sticking to it.I'll give you an example in progress from my own business:I sent out  batch of yellow letters and got a call back from a Reltor about a property in a nearby town.

A person starts a mailing campaign and sends out a batch of mail.

They offered to re run the batch at no cost and use the cards that you use.

So I decided to put my big boy pants on and purchase my first yellow letters. I sent just over 1000 letters to absentee owners around my surrounding area. They went out just before the weekend and now that I just got ...

Ryan,I used their skip trace portal, which allows you to search by name, address, DOB, SSN, and allow you to set an email response once the subject you are looking for apply for credit and update their file with new information, and yes they allow batch orders in 2000 or more at one time.Joe Gore

I batch it into 6 weekly mailings of 10k each.

I placed an order of 20k on 10/28 that was supposed to be split in 4 equal weekly batches starting on 11/1.