I'm with Speedldew here. Spending a little money to fine tune gearing to exactly what you want is, in my opinion, money well spent. I've done one and two tooth chainring changes forever. I also rebuild cassettes for different rides. 12, 13 and 14 smallest cogs and 23, 25 and 28 largest cogs.
I am however, not a fan of double cranksets for myself unless I were to move to a very flat location or I could have my dreams answered and the legs I had 40 years ago returned. I ride the double crankset gearing that gives me a fine selection of options plus a tiny inner ring to make hill climbs a joy. (That's where my heart really lives.) My two current geared bikes have 52-42-24 X 13-28 7-speed (or 12-21 7-speed if I want to ride faster) and 50-38-24 X 12-23 to 12-28 9-speed. (I've had to accept that the old 52-42-28 X whatever no longer gets my up everything. I guess it might if I let that "whatever" grow to huge cogs but I set the limit at 28 to keep spacing down and gear choices up.)
Ben