Buy eight 2nd hand Cubo 18s or build two good ones?

Someone is selling eight Cubo 18s for a decent price, about 2/3 of the cost of building two myself with the best/most recommended driver: B&C 18DS115. 
The Cubo 18 that are for sale have P Audio P180-2241 drivers, which aren’t optimal according parameters recommended by Cubo. And it would be a lot easier to transport two speakers instead of eight.
Third option would be to build two speakers with less optimal drivers that cost half of the 18DS115 but have better specs than the P Audio drivers in the second hand boxes.
Money is definitely a big consideration, but so storage space and transport. I have put the prices in South African Rand to give an idea of the difference in price.
Use case would be mostly indoor parties with 100 to 500 people, but at least once a year outdoors for about 100 pax.
P Audio P180-2242 driver 
Power rating: 1000 W (AES)
Fs: 37Hz
Qts: 0.48
Vas: 231 L
EPB: 77
R22,000.00 for eight boxes
B&C 18DS115 driver
4 ohm or 8 ohm
1700 W nominal power handling
3400 W continuous power handling
Fs: 30Hz
Qts: 0.2
Vas: 168 L
EPB:  150
R15,199.86
B&C 18TBX100 driver
8 Ohm
Nominal power handling: 1200 W
Continuous power handling: 2400 W
Fs: 34Hz
Qts: 0.35
Vas: 212 L
EPB:  97,143
R8,995.00

Every doubling of cabinets in a bass stack will give you a free 3 dB more output. So 8 cabinets will have 6 dB more output, a 100% free, than 2 cabinets (everything else equal). A 6 dB increase is a doubling of intensity, or equal to 4 times the power amplifier wise, so 8 cabinets will be hard to beat by any 2 drivers in Cubo's. And 8 cabinets are the only real option for 300 - 500 or more people (if the other options are just 2 cabinets).

You can start with higher quality drivers in smaller numbers but that will limit the amount of people you can supply sound for.. Upgrading the drivers two at the time is a viable option. Upgrading drivers can both increase output and sound quality.