Change the layout, trench the slab! Hurray for scope creep!
I made wonderful food and enjoyed a lot of time with my friends and family in a kitchen I hated for ten years. If I had liked the cabinets or counter tops, or had the gumption to paint them, I'd still have that kitchen.
But it doesn't make sense to put new counters on awful cabinets, and replacing both at once is expensive. Most the of people I consulted just asked if I was keeping the existing floor plan and advised that doing so would be more affordable - they didn't explore or evaluate beyond the cabinets they were selling.
Turns out that moving plumbing really isn't the big deal I imagined, especially if one is changing cabinets anyway. The functional advantages to changing my layout cannot be overstated - and it looks better, too.
Advice: Do not spend five figures on a remodel without being sure your layout is optimized, and don't accept someone's word that you can't/shouldn't do something just because THEY can't/won't get paid for doing it.
(ok, who else wants a turn up on this soapbox?)