hi brendan.im afraid im scratching my head also.perhaps if i were to understand your reason for the initial question i might be able to answer it
your child got into grammar and was also offered a kehs bursary? was this a full bursary?
if so im struggling im afraid with your question. i was in the same position ie daughter passed grammar which in itself is a huge achievement and was then offered a place at kehs.there was no question about which to choose.hope you chose kehs maybe are girls will become friends
To obtain a "full" bursary (by which I assume you mean 100% of fees) you have to be able to show a household income of less than £19,500 pa. At that point KEHS will be a cheaper option than any GS because all expenses are met by the Foundation.
For anyone else there are still fees to find, and because of the way the scheme is structured it becomes more difficult to fund the more you earn; there is in effect a "middle ground" where people earn too much to obtain effective support but not enough to be able to pay the fees. So I'm somewhat mystified why you think there would ever be "no question" about the choice. An assisted place is not a panacea; many (perhaps most) people who are offered assisted places turn them down.