hi,
if i would move 1.000 domains to a new registrant in one time i will need to pay the transfer for 1.000 domains? :) or is there any promotion that can i use to move all...

1. If you move a thousand domains to a single new registrar, that registrar would be very happy.
2. Since you'll be moving quite a number of domain names, why not contact the registrar directly and the sales people probably can give you a higher discount than using coupons from them.
3. If the domain names are of different TLDs, you might look into the option of moving them to different registrars. It's two things: first, you're not putting all your eggs in a single basket hence you'll be a little more secure, and secondly, you can take advantage of different pricings of different TLDs of different registrars. So you might be moving your .com domains to registrar A, but .net domains to registrar B since .net's are cheaper in registrar B then in registrar A.

For high volumes moniker, namecheap etc are good.
I'm sure they'd be glad to give you a special discount if you speak to sales directly.

I would contact several different registrars and let them know what you are wanting to do. They could then tell you what kind of pricing they could offer you.

Always contact a registrar before moving such a large number of domains it is likely that they will offer you discount pricing from what is offered on their website.

Contact sales directly. For high volumes thay will offer you a discount. You can check ResellerClub and contact them.
Good Look!

All above comments are good, contact the registrar, and make sure you get a good deal, remember .net is cheaper than .com so if you get offered .com and .net for more than 7.37 its not a great deal.
They get a lot more back from the .net ;)

Check out fabulous.com, they have currently a transfer-in promotion (not sure if it's only for current clients).

adapter said "registrant", not registrar
If you want a registrant change most registrars allow changing the registrant without the need of a transfer, registrars like namecheap, godaddy, netearth and others allow to move a domain from one user account to another user account without any cost, this also doesn't involve a renewal of the domains.
If you mean a registrar change then follow all other answers in this thread, contact the registrars, they will make you a good offer

You won't get better than $7.06 at Fabulous. Contact them.

You won't get better than $7.06 at Fabulous. Contact them.
Sorry Stub, I dont agree with that comment. You can get resell.biz for $6.95.
Depending on the mix of domains, .net could be $5.83 if the OP had 50 percent .NET say, he could get .com/.net down to $6.50 even. Because you play the numbers game then.
elmister, I should have pickled that up as well...

Sorry Stub, I dont agree with that comment. You can get resell.biz for $6.95.
The price Stub referred to was for .com. Fabulous offers currently all domain extensions which they have (not many) at cost for transfer-in.
There are registrars selling below cost.
I agree with Stub that you can't get a better (better, not cheaper) deal than what fabulous is offering at the moment.