C.C.
We always have our accountant do our taxes (because we own a business, so our taxes are fairly complicated), however one year I received a revised 1099 from my retirement account and we had to file an amended tax return. If all you need to file is a 1040x, I don't think it's necessarily that complicated. You have to file revisions by mail (not online). So, sit down with the 1040 you already filed, and put all of those items in the first column (where it says "original amount"). Then, simply add the amount listed on the 1099R you received in the "revised amount" of the 1040x. Add everything up like the form says, and then whatever your new adjusted income is, look that up on the tax table for the amount you owe. Unless it is a huge sum of money on the 1099, it probably won't throw you into the next tax bracket, and is unlikely to change the amount you owe all that much. Maybe wait for your refund, and then when you receive that, put your 1040x in the mail with a check for whatever you owe for that. It will take the IRS forever to deal with your revised return, so I think the advice to wait for your refund from your original filing before sending your revised return was good advice.
Honestly, $100 to fill out a 1040x seems like a LOT. It's only a 2 page form, and unless you're itemizing, it should be fairly straightforward, I would think.