Whilst I do like this addition... how many times do we actually buy sufficient numbers of an item to make this worth it?
When not WAGRing - you do it so rarely - that it's not worth the addition - you maybe buy all the coaches from an SO set - or very rarely buy 100 bulkies for a contractor. Once or twice a week?
When WAGRing - well 100 just does not cut the mustard - I buy 10-20,000 at a time - and would buy more if I could do it quickly.
Basically - to me this is a load of time spent developing a change that simply does not do the job.
If you had simply introduce a super WAGR - costs 1000 times the cost of regular and gives 1000 times the exp of WAGR. Players would have a much faster way of WAGRing. The server gets 1 buy / sell message per 1000 WAGR - which massively reduces server load and 'delivering' time. Winner winner chicken dinner