Forging benefits don't affect ritual costs, though; Dwarven Hammers would be loads better if they did. Given how they're already really good, that's saying quite a bit.
That said, yes, unless Vanarus goes with an astral build on a mobile pretender chassis (to go out and search for free; the astral site search spell is one of the most expensive of its kind), it has very few native options short of empowerment, and I think it costs something like at least 100-120 gems to hit S3 (50 gems to reach 1, then I forget what the costs are for 2 and 3). Unless you have immortals (since they can't be permanently killed inside your dominion) or you're at a threshold value to unlock key items or spells that you cannot bootstrap into in any other way, it's almost never worth it; I'd go one further and say it is never worth it to pay the 50 to break into a new path in multiplayer, since you should typically be able to arrange a trade with someone else unless you're in dire straits, in which case it likely won't pay off in time to save you. You also end up with a sort of catch-22 with initial empowerment, where you can't find most sites to gain gem income (unless they have crosspaths) until you have the paths, and you can't gain the paths to find sites until you have the gem income. Alchemizing might be a consideration, but it is even worse for your cost-benefit ratio due to turning that 100-120 gems to what is at the worst a 200-240 gem cost. Rus doesn't go full astral until LA and Bogarus; Vanarus' only native option is a Gamayun (Conjuration 5, S2s that require S3 to summon) or Vilas (Conjuration 7, S1 requiring A4 or N4 to summon).
By the bye, since I mentioned those two conditions, I don't meet all the criteria. I can't give away my paths by saying I went astral or no because it will allow anyone watching to infer my bless (astral, after all, has an opportunity cost), but I can tell you that I definitely went for an immobile chassis, to wit a Monument. This has informed much of my strategy, to wit my obsessive concern over my capital's security. My early-game passivity was largely due to the failure of effective negotiations with USEC's Ulm, which led to what I referred to as a "deathball" stuck on my capital.
Also, since we're talking Dispel, I actually think it is worthwhile in some circumstances. A minimum of 30 gems to force an opponent to waste anywhere from 50 to 100 gems is a good trade, as long as you succeed. Some rituals are bigger targets than others as well; Utterdark is an obvious target, but Eyes of God a bit less so. Also, don't forget how paths above the minimum add to the cost. A minimum-dispel of 30 gems cast by an S4 counts like a dispel of 35 gems cast by an S3. This works the other way, too; if, for a random example, an S4 caster is casting an S3 global ritual, that 1-path difference counts for 5 extra gems against any attempt to dispel or steal the ritual, even before you count any extra gems you added in. This also scales linearly; an S9 casting Dispel without any extra gems possesses six paths more than needed for the ritual, which means that it counts like a S3 casting Dispel while burning an extra 30 gems. Both global rituals and dispels are more cost-efficient the more powerful your casters are in that path. That's one of the weakness of countries with many but shallow paths; lots of flexibility, not much specialization.