Although it has been a while since I have done it,
adding pages to a US passport did not involve removing anything.
20 extra pages or so were affixed between pages 18 and 19 with a notice that a supplement was added stamped on the first of the extra pages.
Extra pages were numbered A to X to differentiate from the other pages with numbers on them.
The pages were taped in, so there was clear tape over some old visas. Clearly visible, but I don't know how it would affect the validity of any new ones. You may want to have the extra pages put in first so they don't put any tape over a valid visa. A less scrupulous border official would use that as an excuse for an extra "fee" (of course, those type would find an excuse no matter what you did:eek3:).

This was 1997, however, so the situation may be different now...

Thanks Chris.

Of additional concern is the time-length your passport is good. If your passport is going to expire in a couple of years, and you want to go to a lot of places, perhaps it would be wise just to get a new passport before getting visas, etc.

It is something to consider...

YMMV

I just renewed 3 years ago.I thought about renewing. But adding pages is "just" $82.I am hoping it is a faster turn around also.

Russian & other visas
 

Last year I needed visas for Azerbaijan, Turkmenistan, Uzbekistan, Kazakhstan and Russia plus a guide in Turkmenistan. All was organised expertly and painlessly by David Berghof of Stantours contactable via STANTOURS - Central Asia Travel Resources. He guided me through the process; arranged the on-line submission of the application forms and all I had to do was send my passport and pay the fees. He is highly recommended.