First build . Got the skills just not the skills

Sorry, my reply wasn't that clear in explaining my reasoning.

The point that was trying to make was that if you are going to itemise the cost of a build down to pence, you really need to include everything. That includes interconnecting cables between amplifiers and speakers, crossover and amplifiers. What about speaker grilles and a rack for the amplifiers? If you buy a ready made, 10m, 4 core speakon cable from Blue Aran, it is £57. If you buy the parts and make your own it is still £42. If the mid/tops need raising up add on the price of speaker poles and fittings. All these items add up, and given that the budget was £1500 to £2500, presumably closer to £1500 would be better. £150 of cables and connectors then becomes 10% of the budget.

I acknowledge that the cost for these parts will be similar whatever the rest of the system is, but so is a box of screws. When working within a fixed budget, all parts need to be taken into consideration. Without them the system is useless. Yay, you came in within budget, but it is a bit sad if you your mum wants her kettle lead back mid gig.

The OP doesn't say what the signal source is. Is he simply using the headphone jack of a tablet/laptop? Does he need a small mixer, or does he already have this part of the system? Is there an additional budget for this? In the end whoever is designing/building the system has to make their own cost list, bill of materials, or whatever you want to call it. We can only assume that his budget is for everything downstream of the mixer and work from that.

The reason for using 4 core cable is that having consistent cable types means less specificity. You just have speaker cables which will work with any cabinet. Given that the OP was asking about a complete system he'll need 4-way for the mid/tops, so may as well get all 4 core. As For use inside the cabinet you can always strip off the outer insulation and use two cores.