c. 1200, "price, value," from Old French cost "cost, outlay, expenditure; hardship, trouble" (12c., Modern French coût), from Vulgar Latin *costare, from Latin constare, literally "to stand at" (or with), with a wide range of figurative senses including "to cost," from an assimilated form of com "with, together" (see co-) + stare "to stand," from PIE root *sta- "to stand, make or be firm."
The idiom is the same one used in Modern English when someone says something stands at X dollars to mean it "sells for X dollars." The meaning "equivalent price given for a thing or service rendered, outlay of money" is from c. 1300. Cost of living is from 1889. To count the cost "consider beforehand the probable consequences" is attested by 1800.
In phrases such as at all costs there may be an influence or echo of obsolete cost (n.) "manner, way, course of action," from Old English cyst "choice, election, thing chosen." Compare late Old English alre coste "in any way, at all."
"be the price of," also, in a general way, "require expenditure of a specified time or labor, or at the expense of (pain, loss, etc.)," late 14c., from Old French coster (Modern French coûter) "to cost," from cost (see cost (n.)). Related: Costing.
mid-14c., encresen, "become greater in size or number" (intransitive); late 14c., "cause to grow, enlarge" (transitive), from Anglo-French encress-, Old French encreiss-, present participle stem of encreistre, from Latin increscere "to increase, to grow upon, grow over, swell, grow into," from in- "in" (from PIE root *en "in") + crescere "to grow" (from PIE root *ker- (2) "to grow"). Modern English restored the Latin spelling 16c. Related: Increased; increasing.
late 14c., "action of increasing; results of an increasing," from increase (v.) or from verbs formed from the noun in Old French or Anglo-French. The stress shifted from 18c. to distinguish it from the verb.
Proto-Indo-European root meaning "to increase." It forms all or part of: auction; augment; augmentative; augur; August; august; Augustus; author; authoritarian; authorize; auxiliary; auxin; eke (v.); inaugurate; nickname; waist; wax (v.1) "grow bigger or greater."
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit ojas- "strength," vaksayati "cause to grow;" Lithuanian augu, augti "to grow," aukštas "high, of superior rank;" Greek auxo "increase," auxein "to increase;" Gothic aukan "to grow, increase;" Latin augmentum "an increase, growth," augere "to increase, make big, enlarge, enrich;" Old English eacien "to increase," German wachsen, Gothic wahsjan "to grow, increase."
late 14c., "become more severe;" c. 1400, "to make larger; become larger," from Old French augmenter "increase, enhance" (14c.), from Late Latin augmentare "to increase," from Latin augmentum "an increase, growth," from augere "to increase, make big, enlarge, enrich" (from PIE root *aug- (1) "to increase"). Related: Augmented; augmenting. As a noun from early 15c.
c. 1400, "anything added, an increase or increment," from Latin additamentum "an increase," from past-participle stem of addere "to add" (see add).
mid-15c., "act or process of increasing," from Latin incrementum "growth, increase; an addition," from stem of increscere "to grow in or upon" (see increase (v.)). Meaning "amount of increase" first attested 1630s.