Murrieta Heights (right by Lester's warehouse) for me, I think it might be the most expensive? But not by much. Instant highway access through the broken walls for coming and going in peace, your own yard to park a 'bob in, Ammunation and LSC just round the corner, have never felt like moving. Almost never have to share it in the session with anyone, unlike the cheapest.
More important than which warehouse is the ability to use your own routes, f*ck the GPS. Highway highway highway. Every time I see someone following the GPS to the Vineyard I chuckle.
So, for high end sales, my routes (and nicknames - Office refers to Lombank, my office):
1. Chumash 1 - the loop at Chumash - highway all the way there
2. Chumash 2 - the house above chumash - highway all the way there and then right and up the hill
3. Office 1 - Mansion next to the pink slip race start - highway to just before the vespucci tunnel, turn right to go past office, voila
4. Office 2 - "Paparazzi mansion" in hills - as above
5. Office 3 - Vineyard - as above, plus work out the fastest way from the low road to the corona (little offroad section through vines)
6. Bank 1 - Mansion above PacStandard bank - No highway, just drive to Pacific Standard Bank and turn right
7. Bank 2 - Same
8. Farm - Highway to Madrazo's farm, simple
Hmm, I could have made a map faster Maybe later.