Those who are putting forward the view that some of the big charter boys (Britannia, Monarch etc) don't ask wannabees for a payment for type rating are not entirely correct. They only take low hours non-rated guys through the CTC scheme (unless you are the lucky 6 or so who get sponsored in full), which requires not only an up front payment (£6K or so), but if you are successfully plucked from the holding pool, then 6 months wage free flying with no guarantee of a permanent place.
You may not need to to dip your hand in your pocket for £20K, but the final cost to you in terms of payments to CTC and wage free living for 6 months isn't far from it.