Good help is very hard to find, and I a pay a premium for it when I do, but the catch is how do you know it is good help until you work the guy?
These guys are probably in the same boat, you can talk a good game but they really don't know who you really are, until they see how you perform.
If I had a dollar for every electrician that ever walked into my office and talked a great game, then later turned out to be a dud, then I could retire.
My suggestion, tell them you are willing to make a lateral move, with the opportunities to move up once they see how you perform, but you will not settle for less than you are making now. That is reasonable, and if they are still trying to low-ball just walk away.
It never looks good to take a pay cut to go work for someone else doing the same work, and as an employer I would wonder what was wrong with you if you did.
