Capacity refers the amount of allowed animals in Listings or Collection, as determined by a MorphMarket member's plan level. These limits, as well as other benefits, are shown on the pricing page. The FAQ at the bottom of the page gives more details about how these are calculated.
For some plans, there is a maximum dollar amount for Listings. In this calculation, each individual listing is capped at a maximum value of $10,000. This means that no listing will add more than $10,000 toward the total. "Inquire for price" ads are also assessed at $10,000 each. For this reason, a seller might have $90,000 of listings in 3 ads, but the total capped value which is used is only $30,000 and would fit within the Standard plan.