I try to express my thoughts better. (My english isn't the best, I try to be clear)
Mage Wars producers wants to make products for the majority, e.g. 7th Dispel: the majority play with 1 core or at least has friends for casual plays, who did't buy MW. So they can use 7 copies often.
I see that the argument about having the 7th "useless" Dispel affect only a few players (who probably have enough money because his friends have the core set + spell tomes too, or if they haven't, the 7th Dispel wouldn't be useless for them).
And I think you can't say to buy singles, because it's not in the "plan" (and I have other problems: shipping, tax to EU, won't be cheaper) . The plan is to make products for the majority. The producers don't want to force you to buy singles, only if you have special wants. At least I read they words so.
So at this point I can't see why is this good for the majority. If they put mages in the spell tomes it's ok, because at that moment you can use those spells.
I'd like to see what's the official response.
p.s.: I don't want to lay to charge (maybe not the best expression, sry my lack of english). Everybody at MW was so helpfull with me and others, and they answered everything logically. I just really want to understand why is this good, or what's the plan.