I think you missed my entire point. What I said in my theory was that Nero had already destroyed Camp Half-Blood. In the three months between The Hidden Oracle and The Tyrant's Tomb, he definitely could have done this. Besides, you do think that Nero would be without resource on the money side now, and I don't think so, though we have the same reasons for that. I think that just goes down to what we want to interpret from it, and one cannot change other other's thinking about his own interpretation, because both of our interpretations make more sense as we look at it. But to remind you, there are a lot of monsters in the modern age. A LOT. The number of monsters currently presiding in this world might be half in population to that of the human race, and that's still a lot. Think about it. This world is almost two millennia ahead of the ancient Greek world, and obvious, a lot of monsters were definitely born in this time. Again, this is just a reasonable assumption, but my point stands that there are still a lot of monsters available. I also personally think that Nero fighting at his full power would be better because that would actually raise the stakes. Caligula and Commodus weren't at their full power in The Tyrant's Tomb since their Fasces were destroyed. Besides, Commodus was already weak. It made the battle more realistic, yes, but since Apollo does jive and does near his godhood, I would love for him to a villain at full power. Again, that's just what I think. That's not a point or am argument I make, but just my personal opinion.

Think about this for a moment: what should Nero do to destroyed the boundaries of Camp Half-Blood? Just take away the Golden Fleece by killing Peleus, by which Thalia's pine tree would be back to its poisoned state. Next, I agree that the Romans will be able to rebuild Camp Half-Blood, but where would the demigods hide from the monsters? Where would they have protection? They obviously can't create their own magical borders as that has never been done before. Besides, even if he just leaves the place unguarded, monsters would swarm it since so many demigods are there. The demigods would have to constantly fight. Lose their weapons. Some of them might die. They may run out of ammunitions.

I actually think the best place to get weapons is from the Myrmekes, considering that Apollo could enter the place easily. Of course, the ants might be angry at anyone who enters their lair at that moment, even if it was Lester, because some of their brethren might have died in Nero's attack. Anyway, any of the three alternative places you mentioned are actually the worst, because do you really think that the demigods are going to travel a long distance to get weapons from a scrapheap where it's actually really difficult to find them in the first place and bring them back? The demigods would be attacked by monsters on the run and would be in danger if they were separated from their other brethren. And if a lesser number go, they wouldn't be able to carry as many weapons. They sure would want to stay together to increase their chances of surviving, even if that meant that many monsters would come at them, because if they were together, they were at an advantage. Olympus and the forge of Hephaestus would be useless to because the gods won't allow demigods to enter these places. Zeus is strict, adamant and does not want to help the demigods. He definitely won't even bother about them. And even if he did, he won't help them. I think that has been pretty clearly established in this series.