Dante wrote:
...snip...At first glance, the monetary costs seem high for the low-level spells, but I do not know whether they are too high to be practical. The number of spells presented seems reasonable given the limitations on the pacts.
IMO yes the costs are usually "absurdly" high for what they do. Cast a spell in one scene or stock up on permanent runes? But the Tier II & III Summoning spells might have utility at higher tiers if PCs are flush with cash to burn. There's a lot more cash at Tier II than there was at Tier I. That trend may continue in Teir III and beyond. Or not - we'll see. Since there are no other Tier V spells in the game, the cost is just the price of admission to greater power than you could normally get.
Given the way the pact/binding works (its a binding you cast in a preceding scene that lasts until you summon the creature) I think you can use the sorcerous pact summoning and then cast another binding spell/summoning (like summon elemental) ... which could be cost appropriate if you were in the final fight of a BI fighting something like Uhxbractit and needed two extra soldiers on your side.