It always was the case though piegonk including the OEM. In my day (heavy construction machinery) I'd get to preferred bidder status after submitting a budget price and 'on site' demo's, then it was usual prior to orders being placed for a final discussion and the adding of extras, recommended spares etc. When this was agreed in principle a final detailed quote was submitted along with delivery times and payment terms. In every case for projects over £500,000 it was as you say. In fact the original budget price was often different to the final bid. In the Brexit case where billions are involved, it is impossible to firm up on anything at the moment until every aspect has been discussed. At this moment these have not and in my opinion politicians on both sides are simply trying to score political points on what might happen. I am a Tory but feel both TM and Davies struggle to put this point to the voters. It is very easy for the opposition to sneer and pick fault with everything, although I do believe Parliament should be given a final vote. How nice it would be for Corbyn and his crew to occasionally stop carping and welcome certain principles agreed.