OK, so I finally bit the bullet and purchased my airfare. A friend I'm traveling with is flying from Boston to London, and has offered to let me spend the night at her house, then we'll all drive to Boston together the next day. This takes care of the worry of having to book a separate ticket from Columbus. So I was able to book Icelandair from Boston to LHR. The ticket was a hair over $900. So even if I end up spending the current $400 to get to my friends' place, $1300 is definitely less than $1750.
AND! There's a bonus. I'm going to take advantage of Icelandair's no-cost "Stopover" program, and spend a day and a half in Reykjavik, Iceland on my way home!
I've been reading up on the Reykjavik area, and it sounds like a place I'll really enjoy visiting. I'm beginning to think I should have planned more days there!
It's nice to have a decision made. With my luck, the airfare will plummet now that I've purchased mine, but that's always the risk we take!
Thanks everyone for all the input! I really appreciate it!
Sayhello