Apparently division of military retirement and TSP are complicated and unique enough that you need a specialist to make sure your settlement agreement contains the proper language for the government to administer the division. I didn't have TSP, but we hired a specialist to draft a QDRO for division of my military retirement. It's necessary to get the language just right so that my ex can be paid directly from DFAS.
The guy we hired for the military pension QDRO charged a flat fee of $850 to draft the QDRO and review the language in the settlement agreement, so $1,600 sounds a little steep to me. And even though it's specialized I would think the same attorney could do both the retirement and TSP orders. If you're in California PM me and I'll give you the contact info.
A couple of other items on military retirement to consider:
1. If you elected to take the Survivor Benefit Program, you should make sure that the order requires your ex to maintain it with you as beneficiary. Typically the SBP premium is deducted from "disposable military retired pay" prior to division.
2. If your ex is receiving VA disability compensation and is rated less than 50% disabled, the VA money is also deducted from disposable retired pay--meaning that your ex gets 100% of the VA money, and you split what's left according to the agreed-upon percentage. This presents an opportunity to the service member to increase disability rating and effectively get a larger share of military retirement compensation. You should look for language that adjusts your percentage of the split so that what you get is equivalent to what you would get if the VA money was not deducted. If your ex's rating is above 50% he's eligible for concurrent receipt so he'll get the VA money and you'll split the entire amount of his pension.