Not sure of availability in the US, but Golden Promise is supposed to be Scotland's answer to Marris Otter and it is supposed to produce a much better yield than Marris Otter which might make it quite a bit cheaper. (Worth looking into.)
-I also don't have a grain mill but want to avail of bulk malt prices; pretty easy solution is just to find 1 or 2 other people and split a bag of pre-crushed base malt with them. Especially if you buy it right before you plan to do a 15 gallon RIS you'll only have a few months left of grain, anyway.
If you can find golden promise cheaper you should jump on it because the farmers have been having a difficulty growing this variety and it's acreage is being phased out pretty quickly. (It was being used both for beer and Whiskey so had some good acreage before.)
-Some untrained pallets often mistake the honey biscuity flavor of MO and Golden Promise for diactyl when the percentages of base malt go up so it's worth watching the total percentage if you have snobby friends who see diacetyl around every corner.
I've had some absolutely fantastic "english inspired" beers made with Gambrinus ESB malt at Black Raven in Redmond, Washington, too for what that's worth. (Two malts worth doing the price comparison on for sure.)
Adam

